Preheat oven to 350F. Line an 8-inch square pan with aluminum foil leaving overhang and spray with cooking spray, or grease and flour the pan; set aside.

In a large microwave-safe bowl, melt the butter and chocolate together, stirring every 30 seconds until smooth.

Allow mixture to cool slightly. Add the eggs, sugar, vanilla, and optional coffee and espresso, whisk vigorously.

Stir in the flour, salt, pumpkin puree, and egg yolk until just combined.

Pour batter into prepared pan, smoothing the top lightly. Mix pumpkin layer ingredients, then spread evenly over brownie batter.

Sprinkle chocolate chips over the top and bake for 35 to 40 minutes, or until a toothpick inserted into the center comes out with moist crumbs.

Allow brownies to cool on a wire rack for 2 hours before slicing. Store in airtight container at room temperature for up to 1 week.