Melt butter in a microwave-safe bowl in 30-second increments until fully melted.
1 stick Butter
Let butter cool slightly before adding in brown sugar and egg plus egg yolk.
1 cup Brown sugar, 1 Egg Plus 1 Egg Yolk
Stir together, then add in vanilla extract.
1 teaspoon Vanilla Extract
Once all the wet ingredients are mixed together, add in flour, espresso powder, baking soda, cinnamon, and salt.
1 3/4 cups Flour, 1/2 teaspoon Baking Soda, 1 tablespoon Espresso Powder, 1/2 teaspoon Cinnamon
Stir until the flour is almost mixed in before adding toffee bits and chocolate chips.
1/2 cup Toffee Bits, 1/2 cup Semi-Sweet Chocolate Chips
Cover and place in the fridge for about 30 minutes to chill.
Preheat oven to 350 degrees.
Using a small cookie scoop cookie dough onto a parchment paper-lined baking sheet leaving about 2-3 inches of space. Bake for about 15 minutes.
Let cool slightly and enjoy!