½ cup (100 grams) granulated sugar½ cup (110 grams) firmly packed light brown sugar½ cup (120 grams) crème fraîche, room temperature½ cup (120 grams) heavy whipping cream, room temperature⅓ cup (76 grams) unsalted butter, melted1 large egg (50 grams), room temperature1 large egg yolk (19 grams), room temperature2 tablespoons (12 grams) packed lemon zest2 teaspoons (8 grams) vanilla extract1 teaspoon (4 grams) almond extract1½ cups (188 grams) all-purpose flour¾ cup (72 grams) natural super-fine almond flour2 teaspoons (10 grams) baking powder1 teaspoon (3 grams) kosher salt¾ cup (200 grams) Lemon Curd (recipe follows)⅓ cup (26 grams) sliced almondsGarnish: confectioners’ sugar
Preheat oven to 325°F (170°C).
In the bowl of a stand mixer fitted with the paddle attachment, beat granulated sugar, brown sugar, crème fraîche, cream, melted butter, egg, egg yolk, lemon zest, and extracts at medium speed until well combined, about 2 minutes, stopping to scrape sides of bowl.
In a large bowl, whisk together flours, baking powder, and salt. With mixer on low speed, gradually add flour mixture to sugar mixture, beating just until combined and stopping to scrape sides of bowl.
Spray a 9-inch springform pan with baking spray with flour. Line bottom of pan with parchment paper. Reserve ¾ cup batter. Spoon remaining batter into prepared pan, spreading into an even layer with a small offset spatula. Spoon Lemon Curd, 1 tablespoon (16 grams) at a time, onto batter in pan. Spoon reserved batter between curd dollops. Using the tip of a sharp knife, swirl curd into batter, being careful not to overmix.
Bake until a wooden pick inserted in center comes out clean, 40 to 50 minutes. Sprinkle edges with almonds. Let cool in pan on a wire rack for 10 minutes. Carefully remove sides of pan; let cake cool completely on pan base on wire rack. Remove pan base, and discard parchment. Just before serving, garnish with confectioners’ sugar, if desired.