Preheat the oven to 425°F. Line a 12-cup muffin tin with liners and set aside.
In a small saucepan over medium heat, brown the butter, stirring occasionally until golden brown and nutty-smelling. About 5-10 minutes. Remove from the heat and let cool slightly.
In a large bowl, whisk together the pumpkin puree, browned butter, granulated sugar, brown sugar, eggs, vanilla, and instant espresso until smooth.
In a separate bowl, whisk together the flour, baking soda, baking powder, cinnamon, and salt. Add the dry ingredients to the wet ingredients and gently stir until just combined. Fold in the chocolate chips, reserving a few for the tops if desired.
Divide the batter evenly between the muffin cups, filling each about ¾ full. Sprinkle with additional chocolate chips.
Bake at 425°F for 5 minutes. Without opening the oven, reduce the temperature to 350°F and continue baking for 20–22 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Let the muffins cool for a few minutes in the pan before transferring them to a wire rack.
