1. Preheat oven to 350 degrees. Butter two 8-inch cake pans; line with parchment paper. Set aside.

2. In the bowl of an electric mixer fitted with the paddle attachment, beat almond paste and butter on medium speed until light and fluffy, about 4 minutes. Add sugar, and beat to combine. Add eggs and vanilla extract, and beat to combine. On low speed, beat in flour, baking powder, and salt until combined.

3. Divide batter between prepared pans. Spread the batter evenly with a rubber spatula. Bake until golden brown, about 25 minutes. Transfer to a wire rack to cool for 20 minutes. Remove the cakes from the pans, remove parchment, and return to the rack to cool, top sides up.

4. To assemble the cake, place the first layer in the bottom of an 8-inch springform pan. Spread half the lemon curd on top, and cover with the remaining cake layer. Spread the remaining curd on top. Refrigerate for at least 4 hours to set.

5. When cake is set, remove sides from springform pan. Press streusel onto sides of cake. Serve.