Directions

1. Preheat oven to 350℉. Coat a 9-inch cake pan or removable-bottom springform pan with cooking spray. Line the bottom with parchment paper.
2. Whisk egg yolks, orange zest, almond extract and 1/4 cup sugar in a large bowl until combined, about 1 minute. Using a spoon or spatula, gently stir in almond flour, baking powder and salt.
3. Beat egg whites in a medium bowl with an electric mixer on high speed until foamy, about 1 minute. Slowly add the remaining 1/4 cup sugar, beating until stiff peaks form, about 2 minutes.
4. Add one-third of the beaten egg white mixture to the egg yolk mixture, gently folding until smooth and lightened. Fold in the remaining beaten egg white mixture carefully until just combined. Spread the batter into the prepared pan; top evenly with sliced almonds.
5. Bake until a wooden pick inserted in the center comes out clean, about 30 minutes. Let cool in the pan on a wire rack for 10 minutes. Remove from the pan and carefully place, almond-side up, on the rack. Let stand until cooled completely, about 30 minutes. Garnish with confectioners' sugar and/or orange zest, if desired.