Step 1

Preheat the oven to 350°F. Lightly coat a 9 x 13-inch baking dish with cooking spray.

Step 2

In a stand mixer fitted with the paddle attachment, combine the lemon cake mix, half the melted butter, and 1 of the eggs. Mix until a consistency of cookie dough is reached.

Step 3

Press into the bottom of the baking dish in an even layer.

Step 4

In a large bowl, beat the cream cheese and mascarpone cheese until smooth. Add the remaining 2 eggs, remaining melted butter, the vanilla, and the lemon zest. Mix well.

Step 5

Slowly add the confectioners' sugar, scraping the bowl down as you go, until light and fluffy.

Step 6

Pour the mixture over the cake base.

Step 7

Bake for 40 to 45 minutes, until the top is lightly golden and the crust is starting to crack.

Step 8

Cool and cut into bars to serve.