Preheat the oven to 350°F. Spray an 8×8-inch baking pan with cooking spray or line with parchment paper.

In a small saucepan on medium heat, brown the butter, stirring constantly to avoid burning. Once it turns light brown and smells nutty, scrape it into a bowl and let it cool for 10 minutes.

Mix the espresso powder into the cooled browned butter.

Add the brown sugar, egg, vanilla extract, and almond extract (if using) to the butter mixture. Whisk until smooth.

Fold in the flour and salt until just combined.

Fold in the chocolate chips and toffee bits (reserving some for the top if desired).

Pour the batter into the prepared pan and smooth the top.

Bake for about 25 minutes until the edges just start to pull away from the pan and the center is set but still soft.

Let cool, then cut into squares and enjoy!