Lavender, Lemon, & Honey Semifreddo Cake

A big part of what I do here is try to make recipes accessible and manageable.  This is especially true for more complex, multi-stage recipes like this one.  I hesitate to call this a difficult recipe, but if you go in half-cocked it will definitely be difficult.  With the right gear and a bit of reading though, it's actually surprisingly hands off.  If you don't have the ideal gear (more on this in a moment), there are some instructions to help you on your way, and there's also a simplified and super-easy recipe variation that you can throw together in under 30 minutes.  In fact, if you have a high-speed blender like a Vitamix, that recipe can be combined with this one to simplify things considerably.

I generally try to build my recipes around the minimum amount of kitchen gadgetry, and to provide options and alternatives wherever possible.  That being said, this recipe is MUCH easier to handle if you have a stand mixer.  It's not impossible without one, but you'll need more patience, some arm strength, and a few more steps if you're going to use a hand mixer only.  If you're some kind of masochist who likes to hand-whisk things, this is still doable, but get ready for an arm workout that'll make Thor nod approvingly.  I guess we weren't done with the comic book references.  In short, you'll need to whip the whites and yolks separately for both the semifreddo and the cake portions of the recipe.  For the details on this method, check out the notes in the recipe card below.

I made the semifreddo in this recipe the old-fashioned way; i.e. with a double-boiler (bain marie) and the stand mixer.  If you have a Vitamix or other high-power blender, you've got the opportunity to simplify this step considerably by using the semifreddo technique in this recipe.  If you do use the double-boiler method, you don't need a specific pot - I just float the mixing bowl in a large pot of water (e.g. a Dutch oven).  A food thermometer takes the guesswork out of getting the semifreddo to the right temperature, so that's really nice to have too.  Lastly, a kitchen scale is nice to have for the sponge cake, as you'll get somewhat more consistent results by using weights instead of volumes.

This sponge cake recipe is all about the air.  There are no leavening agents, and a fairly minimal amount of flour.  Instead, the light texture of the crumb is derived from the air that's whipped into the eggs.  Without enough air, the sponge will be too dense.  This is the first part of the recipe where you'll notice the distinct advantage of a stand mixer.  Using one allows you to prepare the cake batter with whole eggs and without having to actually hold the a mixer for a prolonged period.  If you're using a hand mixer, refer to the recipe card notes below for information on how to separate and whisk the eggs.

The cake itself is actually quite easy to make as long as you whip the eggs thoroughly and avoid deflating them by over-stirring the flour.  I used two 8 inch cake pans lined with circles of parchment paper and greased with butter, and the cakes came out with zero difficulty.  You could also use a single relatively deep 9 inch pan to bake the cake, then cut the cake into two round halves.  If you opt to go with this method you'll need to increase the baking time to compensate for the thicker cake.

The cake itself is quite simple and not overly sweet, so you'll want to make sure that you don't skimp on the brushed-on lavender-lemon syrup.

As with curds, custards, and sabayons, the biggest technical challenge in this recipe is cooking the eggs into the dessert without scrambling them.  It's actually not all that difficult of a thing to do with a double boiler - the two biggest factors to consider are that you need to stir pretty much the whole time, and that you don't want to rush things.  As I've mentioned above already, if you have a high-speed blender (e.g. a Vitamix) you can actually take a fantastic hands-off shortcut and make part of the semifreddo in there, bypassing the stovetop portion all together.  High speed blenders can whip a lot of air into your eggs, and the heat of the blades and motor will actually cook the mixture for you.  It's similar to the curd making technique I've used before, and it's how I was able to create a simplified 30-minute variation for this recipe.  Honestly, the next time I make this (or any other semifreddo), I'll use the blender to do the eggs. It's just that much easier, and the results are every bit as good, in my opinion.

Now, let's look at a couple of the ingredients in a bit more detail.

I love lavender, but there's a fine line between a lovely floral element in your recipe and a cake that tastes like French soap.  I've aimed to keep things on the subtle side in this recipe.  If you're a huge lavender fan you could consider adding a bit more to either the semifreddo or the syrup, but I would be very careful.  I prefer instead to garnish the finished cake with lavender flowers for a bit of extra kick and for the visual aspect.

I like to keep the semifreddo very smooth and creamy, and as such I didn't use whole lavender flowers there.  Instead, I used a spice grinder (a mortar and pestle would work too) to pulverize the lavender with a bit of sugar, then sifted out any big bits of plant that were leftover.  This is totally optional though, and you can definitely use the flowers as-is if you prefer.

Lavender flowers are often available in the spice section of a grocery store, though the price can be a bit on the high side.  If you're fond of lavender, consider buying a small bag from a local farm (or farmer's market) or online.  It keeps for a long time without losing flavour, and it's generally more cost-effective.

Not a fan of lavender? No worries.  You can omit it entirely and focus on the honey and lemon combination, or add a different complimentary flavour like ginger.  A bit of candied ginger in the semifreddo and a teaspoon or so of ground ginger in the cake would be a great variation.  Cardamom would also be a very nice substitute to use.

Honey is a big deal in this recipe, and definitely not just a simple swap-out for sugar.  The honey plays a huge roll from a flavour perspective, so you'll want to consider it carefully.  Choose a honey that you like, and be aware that a stronger tasting honey will have a more pronounced effect on the semifreddo.  I used a rather bold Tasmanian Leatherwood honey with tons of character, but you might want to go with something lighter and more floral.  You can also drop the honey altogether in favour of sugar, but let me emphasize that this drastically changes the character of the dessert.  The simple semifreddo recipe that I made as a sibling to this one uses sugar instead of honey, and let me tell you it's an incredibly different kind of dessert.  Honey brings distinctive flavours and scents right to the forefront, while the lemon brightens things and the lavender lends a fairly subtle note.  With sugar, however, the lemony character of the semifreddo becomes much more pronounced, and the lavender becomes the sole floral component.  Both versions are delicious, but decidedly different.

It's also worth noting that honey is sweeter than sugar per gram, so make sure to pay attention to the proportions if you're exploring any variations.

Given that this is a somewhat complex recipe, the instructions in the recipe can look a little intimidating.  I'll reiterate that this isn't actually a very technically difficult recipe, but there are a lot of steps and you do want to organize yourself.  I've put detail into the recipe itself so that you know what goes where (and when), but there are a few additional tips for breaking up your work flow and/or getting things done ahead of time.

If you do want to work ahead, you can make the cakes and syrup the day before.  They'll both keep in the fridge quite well.  Be sure to let your cakes cool before putting them in the fridge in a container/bag/plastic wrap.  You can also grind the lavender and sugar together ahead of time if you're so inclined.  For the semifreddo, you can whip the cream much earlier in the day or even the night before, then store it in the fridge.

In terms of work flow, I'd encourage you to take some time to do a few things before you start doing the actual food stuff:

• Cut your parchment paper circles and measure out the aluminum foil piece used to extend the sides of the cake pan upward.
• Make sure that your stand mixer bowl will fit into your double boiler setup.  If it won't, set up an alternative (e.g. a smaller metal mixing bowl).
• Clear your work space, including space in your sink so that you can clean your mixing bowl between steps.  You're going to use that bowl a lot, and the last thing you want is to have no space to clean it up.
• If you're not working with a stand mixer and you need to separate your eggs, separate them ahead of time - even the night before!

I think you'll be delighted by the final recipe, and by how nicely it actually comes together with a bit of planning.  And remember, if you're looking to do something a little easier, this wonderful simplified recipe is a great substitute or partial replacement!  You can easily hybridize the two recipes, and use the high-speed blender version of the semifreddo from that recipe along with the cake portion from this one.