Prepare the Pan

1. Preheat oven to 325°F (160°C).

2. Line a 9 × 13-inch (23 × 33 cm) baking pan with parchment paper or foil, leaving overhang for easy removal. Lightly grease.

Make the Dough

1. In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter and granulated sugar on medium speed until light and fluffy, about 2–3 minutes.

2. Add the powdered sugar and vanilla extract. Mix until smooth.

3. Add the flour and fine sea salt. Mix on low speed just until a soft dough forms. Do not overmix.

Form the Base

1. Press half of the dough evenly into the prepared pan to form the crust.

2. Refrigerate the remaining dough for 20–30 minutes to firm up (this will make it easier to crumble later).

Par-Bake the Crust

1. Bake the crust for 18–22 minutes, or until the edges are lightly golden and the surface looks set.

2. Remove from oven and let cool slightly (about 10 minutes).

Add Caramel and Topping

1. Spread the caramel sauce evenly over the warm crust.

2. Remove the chilled dough from the refrigerator and crumble it evenly over the caramel layer.

Final Bake

1. Return the pan to the oven and bake for 25–30 minutes, or until the top is lightly golden and the caramel is gently bubbling around the edges.

2. Remove from oven and immediately sprinkle lightly with flaky sea salt.

Cool and Slice

1. Allow bars to cool completely at room temperature (about 1 hour), then refrigerate for at least 2 hours before slicing for clean cuts.

2. Use a sharp knife, wiping between cuts.