Preheat your oven to 350°F (175°C) and line a 9x13-inch baking pan with parchment paper.

In a mixing bowl, cream together the softened unsalted butter, light brown sugar, and granulated sugar for 3-4 minutes until light and fluffy.

Beat in the eggs one at a time, then add the vanilla extract until smooth and creamy.

In another bowl, whisk together the all-purpose flour, baking soda, and salt. Fold this into the wet ingredients until just combined.

Press half of the cookie dough into the bottom of the prepared baking pan.

Warm the salted caramel sauce slightly and pour over the pressed cookie dough, then sprinkle sea salt flakes on top.

Crumble the remaining cookie dough over the caramel layer.

Bake for 30-35 minutes until the edges are golden brown and the center is soft but set.

Cool completely for about 1 hour on a wire rack.

Whisk together the powdered sugar, whole milk, and ground cinnamon until smooth, then drizzle over the cooled bars.

Let the glaze set for about 10 minutes, slice into squares or rectangles, and enjoy.