Margarita Cheesecake Bars

Heat oven to 350°F. Line a 13 x 9-in. baking pan with foil, letting foil extend about 2 in. above pan at both ends. Coat foil with nonstick spray.

Spread cake batter in prepared pan. Bake as box directs. Cool completely in pan on a wire rack. Holding foil ends, lift from pan. Trim rounded top (hump) off cake with a long serrated knife until flat. Holding foil ends, return cake to pan.

Pour lime juice into a small saucepan; sprinkle with gelatin. Let stand 1 minute, then stir over low heat 3 minutes until gelatin completely dissolves. Remove from heat.

Beat cream cheese, sugar and lime peel in a large bowl with mixer on medium speed 2 minutes until fluffy. Slowly beat in gelatin mixture. Beat 1 minute to blend. Scrape onto cake, then spread evenly to edges. Refrigerate 1 hour to set, then cover loosely and refrigerate 2 hours or overnight.

To serve: Lift from pan. Cut in 42 bars (dip knife in hot water; wipe clean between cuts). To garnish: With citrus zester, cut peel off lime. Cut lime in quarters lengthwise then crosswise in 11 slices. Top bars with lime and peel. Planning Tip: Can be made through Step 4 up to 1 day ahead. Garnish just before serving.