Brown the Butter: In a stainless steel pan, melt the butter over medium heat, stirring until golden brown, about 5-7 minutes. Cool to room temperature.

Mix Sugars: Combine the browned butter with granulated sugar and dark brown sugar. Whisk until smooth, about 2-3 minutes.

Combine Dry Ingredients: Whisk together all-purpose flour, bread flour, baking soda, baking powder, and salt. Optionally add espresso powder.

Incorporate Eggs and Vanilla: Add eggs and vanilla extract to the sugar mixture. Whisk until fully blended.

Mix Dry Ingredients: Gradually add the dry mixture to the wet ingredients, folding gently until just combined.

Add Chocolate and Toffee: Fold in chopped chocolate and toffee bits until evenly distributed.

Chill Dough: Wrap dough tightly and refrigerate for at least 24 hours, up to 72 hours.

Preheat Oven: Preheat your oven to 350ºF (175ºC) and line baking sheets with parchment paper.

Portion Dough: Scoop out dough onto prepared baking sheets, spacing about 2 inches apart.

Bake: Bake for 12-14 minutes until edges are golden but centers are slightly underbaked.

Reshape: Use a cookie cutter to reshape cookies while warm and optionally sprinkle with flaky sea salt.