NOTE: You can make the syrup up to one week in advance and store covered in the refrigerator. The leftovers are delicious in tea.

In the small saucepan, stir together all the syrup ingredients and bring to a boil.

Remove from the heat and let cool to room temperature. Strain to remove the lavender and zest and keep the liquid.

Note: You can make buttercream up to four days in advance and store covered in the refrigerator. If you want to make it far ahead, you can make it up to one month in advance and freeze it in an airtight container. To use the chilled or frozen buttercream, simply bring it to room temperature and then beat it briefly to restore its consistency.

In the small sauce pan, combine the sugar, water and vanilla bean seeds or extract and warm over medium heat just until the sugar dissolves.

Continue to cook, without stirring, until the syrup reaches 225° F (107° C) on a candy or instant-read thermometer. Once it reaches that temperature, remove the syrup from the heat.

While the syrup is heating, begin whisking the egg and egg yolk at high speed in the bowl of your mixer using the whisk attachment. Whisk them until they are pale and foamy.

When the sugar syrup reaches the correct temperature and you remove it from the heat, reduce the mixer speed to low speed and begin slowly (very slowly) pouring the syrup down the side of the bowl being very careful not to splatter the syrup into the path of the whisk attachment. Some of the syrup will spin onto the sides of the bowl but don’t worry about this and don’t try to stir it into the mixture as it will harden!

Raise the speed to medium-high and continue beating until the eggs are thick and satiny and the mixture is cool to the touch, about 5 minutes or so.

While the egg mixture is beating, place the softened butter in a bowl and mash it with a spatula until you have a soft creamy mass.

With the mixer on medium speed, begin adding in two-tablespoon chunks. When all the butter has been incorporated, raise the mixer speed to high and beat until the buttercream is thick and shiny.

Add the lemon extract and zest and beat for an additional minute or so.

Refrigerate the buttercream, stirring it often, until it’s set enough to spread when topped with a layer of cake, about 20 minutes.

NOTE: Can be made up to one day ahead and stored in the refrigerator.

Melt the white chocolate and the 3 tablespoons of heavy cream in a small saucepan or in a glass bowl in the microwave. If using the microwave, start with 30 seconds on 70%. Stir and microwave for another 15 seconds or so, but do not allow the chocolate to melt completely in the microwave or it might seize. Remove and stir in the last few chunks of chocolate.

Stir to ensure that it’s smooth and that the chocolate is melted. Add the tablespoon of liqueur to the chocolate and stir. Set aside to cool completely.

In the bowl of a stand mixer, whip the remaining 1 cup of heavy cream until soft peaks form.

Gently fold the whipped cream into the cooled chocolate to form a mousse.

If it’s too thin, refrigerate it for a bit until it’s spreadable.

If you’re not going to use it right away, refrigerate until you’re ready to use.

NOTE: You can make the cake up to one day in advance and store at room temperature.

Divide the oven into thirds by positioning a rack in the upper third of the oven and the lower third of the oven.

Preheat the oven to 425°F. (220°C).

Line the two jelly-roll pans with parchment paper and brush with melted butter.

In the bowl of a stand mixer fitted with the whisk attachment (or using a handheld mixer), beat the egg whites until they form soft peaks. Add the granulated sugar and beat until the peaks are stiff and glossy. If you do not have another mixer bowl, gently scrape the meringue into another bowl and set aside.

If you only have one bowl, wash it after removing the egg whites or if you have a second bowl, use that one. Attach the paddle attachment to the stand mixer (or using a handheld mixer again) and beat the almonds, confectioners sugar and eggs on medium speed until light and voluminous, about 3 minutes.

Add the flour and beat on low speed until the flour is just combined, no more than about 15 seconds. Be very careful not to overmix, or the cake will lose volume.

Using a rubber spatula, gently fold the meringue into the almond mixture and then fold in the melted butter. Start with just ⅓ of the meringue and make sure it's folded in, then add another ⅓ and another, folding gently each time. Divide the batter between the pans and spread it evenly to cover the entire surface of each pan.

Bake the cake layers until they are lightly browned and just springy to the touch. This could take anywhere from 5 to 9 minutes depending on your oven. Place one jelly-roll pan in the middle of the oven and the second jelly-roll pan in the bottom third of the oven. Rotate pans as necessary for even color.

Put the pans on a heatproof counter and run a sharp knife along the edges of the cake to loosen it from the pan. Cover each with a sheet of parchment or wax paper, position wire racks over the parchment, and turn the pans over. Remove the pans.

Carefully peel away the parchment, then turn the parchment over and use it to cover the cakes. Let the cakes cool to room temperature. If you are leaving overnight, you may want to lay a tea towel over the parchment to help conserve moisture.

NOTE: Make right before you are ready to finish and serve the cake.

Melt the white chocolate with the heavy cream. Whisk the mixture gently until smooth.

Let cool for 10 minutes and then pour over the chilled cake. Using a long metal cake spatula, smooth out into an even layer.

Place the cake into the refrigerator for 30 minutes to set.

Place a sheet of wax paper on a sheet pan or jellyroll pan.

Using the cookie cutters, cut shapes in the two cakes in multiples of three.

Place the bottom of each mini cake on the wax paper. Brush generously with syrup.

Take the second layer of cake and smear buttercream on one side, and place buttercream side down on the base layer.

Brush the top of the second cake layer with syrup.

Take the third layer of cake and smear buttercream on one side, and place buttercream side down on the second layer. (Optional: You may want to reserve some of the buttercream for decorating.)

Brush the top layer with syrup. Chill in refrigerator for about 30 minutes, until very firm.

Spread the prepared mousse on top of each chilled cake. Refrigerate until very cold and firm, about 2 to 3 hours. (Optional: You may want to reserve some of the mousse for decorating.)