Preheat the oven to 350°F. Have all ingredients at room temperature. Butter and flour four 6” cake pans, or if you’re using a baking spray, apply just before filling the pans. Add wet cake strips to the outside of the pans; this will give you nice flat layers.

Make the vanilla cake

1. In a medium bowl, whisk the dry ingredients together.
2. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, egg whites, vanilla, and buttermilk. The batter will look curdled; this is normal.
3. Add the dry ingredients to the wet and mix until just combined. Do not overmix the batter.
4. Bake until the cakes begin to pull away from the sides of the pans and the centre springs back to the touch (30–35 minutes).
5. Cool the layers in the pans for 15 minutes on racks before taking them out of the pans and letting them cool completely.

Make the chocolate cake

1. In a small bowl, combine the chocolate with the hot water or coffee. Stir occasionally until the chocolate is melted and the mixture is smooth.
2. In a medium bowl, whisk the dry ingredients together.
3. In the bowl of a stand mixer fitted with the paddle attachment, beat the eggs, vanilla, vegetable oil and buttermilk.
4. Add the dry ingredients to the wet and mix until just combined. Do not overmix the batter.
5. Bake until the cakes begin to pull away from the sides of the pans, and the centre springs back to the touch (30­35 minutes)
6. Cool the layers in the pans for 15 minutes. Then, run a thin knife around the edges of the pan and invert the layers onto the racks. Carefully remove the parchment paper and let the cakes cool completely.

Make the Dark Chocolate Frosting

1. In a medium bowl, combine chocolate, cocoa powder, espresso powder and granulated sugar. Add the boiling water. Stir to melt the chocolate, microwaving on half power for 15-second intervals if necessary to melt the last few lumps. Whisk until smooth. Let cool to room temperature.
2. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until smooth and fluffy. Add the chocolate mixture and beat until combined. If the frosting is too soft to frost a cake, refrigerate for 10 minutes or until just firm enough to spread.

Make the Swiss Meringue Buttercream

1. Place egg whites and sugar in a heatproof bowl and whisk until combined. Place the bowl over a pan of simmering water, ensuring the bowl doesn’t touch the water. Continue to whisk until the mixture reaches 160°F or until it’s not grainy between your fingers.
2. Transfer the egg mixture to the bowl of a stand mixer, and beat with a whisk attachment until you get glossy, room temperature peaks. Tip: hold a couple of bags of frozen peas or corn against the outside of the bowl to bring the temperature down.
3. With the mixer running on medium-low, add small chunks of room temperature butter, one at a time. Take your time with this—let the butter incorporate fully before adding the next piece (5–10 minutes). Don’t panic if the mixture gets soupy. Just keep beating. You can’t overbeat it, and it will come together in the end.
4. Add the vanilla extract.

Assemble the Cake

1. Level your cake layers. (We use the “shrapnel” to make parfaits with Luxardo cherries and whipped cream.)
2. Refrigerate the layers before cutting them. Centre a 4” cutter on a cake layer and press straight down. Repeat with the 2” cutter inside the 4” circle. Remove the circles and repeat with the other 3 layers. If you don’t have cutters, make templates from cardboard; just make sure you cut cleanly and vertically.
3. Arrange a vanilla 4” circle between the 6” and 2” chocolate circles and vice versa, applying just enough of the chocolate frosting to hold the circles together. Then, working one alternate coloured layer at a time, apply a thin coat of chocolate frosting to each layer, leaving the top layer bare—Frost the sides of the cake with the chocolate frosting.
4. For the top, pipe vanilla frosting in concentric circles and carefully smooth it to the edge. Refrigerate the assembled cake to firm up.
5. Using gel food colouring, tint vanilla frosting in separate bowls (I use Americolor). This cake used:
6. For the large flowers: 1 c of frosting, Super Red and Lemon Yellow, Russian Piping Tips
7. For the leaves: ½ c of frosting, Navy Blue and Leaf Green, large and small leaf tips
8. For the small flowers: ½ c frosting, Soft Pink and Violet, small open and closed star tips
9. Start by placing the large flowers. Then, I pipe them onto separate squares of parchment, discarding the rejects and recycling the frosting if needed. Freeze the successful applicants for a few minutes to firm up enough to apply to the cake with confidence. Then, fill in with the leaves and smaller flowers.
10. I had enough frosting leftover to frost a dozen cupcakes with the chocolate frosting and decorate them with flowers.