1. Preheat oven to 425°F. Line a 9-inch springform pan with two 15-inch square pieces of parchment paper, extending paper 2 to 3 inches over edge of pan. Place prepared pan on a large rimmed baking sheet.

2. In a large bowl beat sugar and zest with a mixer on medium until evenly combined. Add cream cheese and mascarpone; beat on medium until smooth and sugar has dissolved, scraping bowl as needed Beat in eggs, one at a time, until combined. Beat in the next four ingredients (through vanilla). Sift flour evenly over cream cheese mixture. Beat on low just until combined, scraping bowl as needed. (Mixture will be thin.)

3. Pour into prepared pan. Tap pan on counter a few times to remove any air bubbles. Bake 50 to 55 minutes or until outside edge is set and center is still wobbly when shaken. Cheesecake should be medium to dark brown.

4. Cool in pan on a wire rack 15 minutes. Remove sides of pan; cool completely on wire rack. Gently peel off parchment. Serve at room temperature or cover and chill up to 3 days. Let stand at room temperature 30 minutes before serving. If desired, sprinkle with salt flakes. Makes 12 servings (1 slice each).

NOTE Change up the flavor by omitting the lemon zest and substituting orange-flavor liqueur, kirsch, or raspberry-flavor liqueur for the limoncello.

PER SERVING 502 cal., 40 g fat (23 g sat. fat), 203 mg chol., 425 mg sodium, 30 g carb., 0 g fiber, 26 g sugars, 9 g pro.