Espresso Chocolate Chip Blondies with Brown Sugar Frosting

INGREDIENTS

1/2 cup

unsalted butter (1 stick), melted

large egg

1 cup

light brown sugar, packed

1 tbsp

vanilla extract

tablespoon instant espresso granules

1 cup

all-purpose flour

1/2 tsp

salt, or to taste

3/4 cup

semi-sweet chocolate chips (I used a combo of mini and regular sized chips)

1/2 cup

unsalted butter

1/2 cup

light brown sugar, packed

1 tsp

vanilla extract

salt, optional and to taste