Preheat oven to 350°F (180°C). Spray a 9-inch round cake pan with baking spray with flour. Line bottom of pan with parchment paper.

In a medium bowl, sift together flour, baking powder, and salt.

In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites and cream of tartar at medium-high speed until foamy. Reduce mixer speed to medium-low, and add ¼ cup (50 grams) granulated sugar in a slow, steady stream. Increase mixer speed to medium high, and beat until medium-stiff peaks form. Transfer to a medium bowl.

Clean bowl of stand mixer. Using the paddle attachment, beat butter and remaining ½ cup (100 grams) granulated sugar at medium speed until fluffy, 3 to 4 minutes, stopping to scrape sides of bowl. Add egg yolks, one at a time, beating until combined after each addition; scrape bottom and sides of bowl. Beat at medium-high speed until light and fluffy, about 2 minutes. Beat in lemon zest and vanilla.

Add egg white mixture to butter mixture in three additions alternately with flour mixture, beginning and ending with egg white mixture, folding by hand until just combined after each addition. Gently spread batter into prepared pan. Place fruit on batter. (Do not press fruit into batter.)

Bake until golden brown and a wooden pick inserted in center comes out clean, 30 to 35 minutes. Let cool in pan on a wire rack for 10 minutes. Remove from pan, and serve warm or at room temperature. Just before serving, garnish with confectioners’ sugar, if desired. Store in an airtight container for up to 3 days.