Preheat the oven to 350F, grease a square 8 or 9-inch pan.
Brown the butter on low heat until little it starts to give off a toasted aroma, set aside to cool.
Put eggs and sugar into the bowl of the stand mixer, warm eggs over bain-marie (pan of gently simmering water), whisk constantly for 5 minutes until the eggs are warm to the touch 110-120F.
Whisk in a stand mixer for 1 minute on low speed, slowly progress to medium high for 10 minutes until approximately tripled in volume. Pale yellow, almost white, ribbon stage, hold its shape for a minute.
Sift the cake flour and salt into the egg mixture in thirds, gently folding, use a whisk instead of a spatula to keep the air. Fold until barley incorporated. Add the vanilla to the butter and stir a scoop of batter into the butter and then fold into the big bowl of batter.
Very gently pour the batter into the pan, be careful to not knock any air out. Bake 18-22 minutes, until golden brown. Do not open the oven to check on it or it might collapse.
Cool 5 minutes in the pan and then invert on to a cooling rake.
Italian Meringue Buttercream
In a small pan over medium heat bring the sugar and water to a boil.
While the sugar is boiling begin to beat the egg whites with a whisk attachment, beat until stiff peaks, do not over beat or the egg whites will dry out.
When the sugar reaches 240 degrees F remove from the heat and immediately pour in a steady stream into the egg whites while they are beating. Try and pour the sugar so it doesn’t hit the beater splattering sugar on the upper edge of the bowl.
Continue to beat the egg white and sugar mixture until no heat remains in the bowl, touch the bottom of the to check that is room temperature before adding the butter.
With the mixer still running on medium high speed add the butter a tablespoon at a time, continue to beat for a further 3-5 minutes after all the butter is added. At this stage the buttercream might look curdled, keep beating until it’s smooth.
Finally add the almond extract and pinch of salt, makes about 3 cups of buttercream.
Once the cake has completely cooled trim the top of the cake removing any dome, you want it to be fairly level. Slice the cake in half creating two layers, fill with raspberry jam and sandwich the layers back together.
Frost the top and sides of the cake with the buttercream in a light layer, a little more than a crumb coat but not thick like a final layer.
Roll out the marzipan into a sheet the size of the top of the cake, you can use the pan you caked the cake in as a guide and to cut to size. Lay the marzipan on top of the frosted cake. Chill for about 30 minutes until things firm up.
Now cut the cake into bite size petit fours and frost the freshly cut edges. I find it easier to cut one direction, frost the sides and then cut into squares and coat the remaining un frosted sides. Refrigerate the frosted petit fours and make the poured fondant.
Combine sugar, water and corn syrup in a sauce pan and mix well, cook over low heat, do not heat hotter than 100F, it will loose it’s shine. Remove from heat and add vanilla extract and food coloring.
Place the petit fours on a cooling rack over a cookie sheet to catch the icing and pour or spoon icing over each cake. Collect the drippings, reheat and pour again if necessary for full coverage.