Preheat your oven to 350°F (175°C).

Lightly coat a 9x13-inch baking dish with cooking spray.

In a large bowl, combine the yellow cake mix and melted unsalted butter. Stir until fully blended, then transfer the mixture to your baking dish, pressing it down evenly.

Beat together the cream cheese, granulated sugar, vanilla extract, lemon zest, and kosher salt in a stand mixer until creamy, about 2 minutes. Spread this mixture over the cake base.

Spread the strawberry pie filling over the cream cheese mixture.

Bake for about 45 minutes, until the edges are golden brown and bubbly, while the center remains slightly jiggly. Let it cool for 30 minutes, then cover and refrigerate for at least 4 hours or overnight for best flavor.

Slice when ready to enjoy! Let it sit at room temperature for about 15 minutes before serving. Garnish with fresh strawberries if desired.