Preheat oven to 350°F. Lightly grease a 9x13-inch baking dish or line it with parchment for easy removal.

In a medium bowl, whisk the strawberry cake mix, egg, melted butter, and heavy cream until you have a smooth, thick batter. Stir in the white chocolate chips.

Spread the batter evenly in the prepared pan and smooth the top with a spatula.

Bake for 18–23 minutes, until a toothpick inserted near the center comes out clean or with a few moist crumbs. Avoid overbaking — the bars should remain slightly tender.

Remove from oven and cool completely in the pan on a wire rack. Cooling fully is important so the frosting doesn’t melt.

While the bars cool, make the frosting: beat the room-temperature cream cheese with powdered sugar until smooth. Add the sour cream and vanilla, mixing until combined. Gently fold in the whipped topping until light and airy.

Spread the frosting over the cooled bars in an even layer.

For the crunch topping, pulse the vanilla sandwich cookies in a food processor until crumbly. Transfer to a bowl and stir in the strawberry syrup until evenly pink and slightly sticky.

Sprinkle the cookie crumbs over the frosted bars and press lightly so they adhere. Chill the pan for at least 30–60 minutes to set and firm up the layers.

Slice into squares with a sharp or serrated knife. Serve chilled or at cool room temperature.