Preparation

• Brown the Butter: In a medium saucepan over medium heat, melt the butter and cook, stirring constantly, until it turns golden brown and has a nutty aroma. Transfer it to a bowl, add the espresso powder, and let it chill in the fridge for about 1-2 hours until firm.
• Prepare the Dough: Use a stand mixer to beat the solidified browned butter and both sugars together on medium-high for about 3-4 minutes, or until the mixture is light and fluffy.
• Add Egg and Vanilla: Mix in the room temperature egg and vanilla extract, beating until everything is well combined and smooth.
• Incorporate Dry Ingredients: Carefully add the baking powder, baking soda, salt, and flour. Stir on low speed until just combined—avoid overmixing.
• Fold in Toffee Bits: Gently fold the Heath toffee bits into the dough until evenly distributed.
• Chill the Dough: Scoop large balls of dough onto a plate or baking sheet and refrigerate for at least a few hours, or up to 24 hours for best results.
• Preheat Oven & Bake: Preheat your oven to 350°F (175°C). Place the dough balls onto a parchment-lined baking sheet, sprinkle lightly with flaked sea salt, and bake for 11-13 minutes or until the edges are golden brown.
• Cool & Serve: Allow cookies to cool slightly on the baking sheet before transferring them to a wire rack to cool completely.