Preheat and prep by preheating your oven to 350°F (175°C). Line a 9×13-inch baking dish with parchment paper, leaving a bit of overhang for easy removal later.

Make the cookie base: in a large mixing bowl, whisk together the melted butter and brown sugar until smooth and glossy. Add in the egg and vanilla extract, mixing well to combine.

In a separate bowl, whisk the flour, salt, baking powder, and instant espresso powder. Gradually add the dry ingredients to the wet mixture, stirring until a soft dough forms.

Press and layer the dough evenly into your prepared pan. It may seem a bit thick—that’s perfect! Sprinkle the chocolate chips and toffee bits evenly over the surface. Then, drizzle the sweetened condensed milk over everything. Don’t worry if it pools a bit—it will spread and bake beautifully into the bars.

Bake to golden perfection for 25–28 minutes, or until the edges are golden brown and the center looks set. The aroma of coffee and sugar caramelizing together will fill your kitchen—it’s heavenly.

Cool and finish the bars by cooling completely in the pan before lifting them out. For a final touch, sprinkle flaky sea salt on top to balance all the sweetness.

Slice and serve cooled, slice into squares or rectangles. Serve with a cup of coffee or a glass of cold milk for the ultimate treat.