Walnut-Vanilla Cake

Ingredients

• 1 1/2 cup heavy cream
• 1/2 vanilla bean
• 10 1/2 tablespoons butter, softened
• 2/3 cups brown sugar
• 1 1/3 cup flour
• 1 teaspoon baking powder
• 4 teaspoons espresso powder
• 1 teaspoon salt
• 5 egg yolks
• 1/3 cup milk
• 5 egg whites
• 1 cup granulated sugar
• 2 teaspoons cinnamon
• 1/2 cup walnuts, chopped and toasted
• 1 tablespoon maple syrup

Method 

1. The night before: Separate eggs and let egg whites sit on the counter overnight, covered with a clean cloth. Pour cream into a saucepan. Split and scrape vanilla bean into the cream and heat until just boiling. Remove from heat and let cool. Cover and chill overnight.
2. The next day: Preheat oven to 350° F. Prepare a 9 x 12-inch cake pan with buttered parchment. (Alternatively, you can prepare two 9-inch round cake pans.)
3. In the bowl of a stand mixer fitted with a paddle attachment, cream butter and brown sugar until creamy and fluffy, about 3 to 4 minutes.
4. Whisk together flour, baking powder, espresso powder, and salt. Add mixture to butter and sugar in 3 increments, mixing fully between additions.
5. Whisk together egg yolks and milk. Add to batter in 3 increments, incorporating fully each time. Scrape batter into prepared pan.
6. In a clean mixing bowl (I wipe down my bowl and whisk attachment with vinegar), whip egg whites until foamy. Add sugar and cinnamon and whip to soft peaks.
7. Spread the meringue over cake batter, cover with toasted walnuts and bake 35-40 minutes, until the meringue is crackly. Let cake cool completely.
8. Meanwhile, remove vanilla bean from cream. Add maple syrup and whip cream to soft peaks. Cut cake in half and place one half on a cake plate, meringue side up. Cover with whipped cream. Top with remaining half, meringue side up. You will end up with a 2-layer square cake from your single-layer rectangular cake. (If you're doing this in two round cake pans, just top one with the other.) Let sit 1-2 hours.
9. To go completely over-the-top, serve with a dark chocolate sauce punched up with a few dashes of walnut bitters.