Preheat your oven to 350°F (175°C) and prepare a 9x9 inch baking pan. Line the bottom and sides with foil, lightly greasing it.

In a large mixing bowl, cream the softened unsalted butter until light and fluffy for about 2-3 minutes.

Gradually add the strawberry cake mix, mixing on low speed until incorporated, then add the large egg and mix until a thick dough forms.

Press half the dough evenly into the bottom of your prepared baking pan to form a solid base layer.

Sprinkle the white chocolate chips over the base layer and drizzle the sweetened condensed milk on top.

Crumble the remaining dough over the filling, spreading it to allow some filling to peek through.

Bake in the preheated oven for about 27-30 minutes, ensuring the edges turn golden brown while the center remains slightly jiggly.

Allow the baked bars to cool at room temperature for several hours or ideally overnight before slicing.