Preheat oven to 350°F. Line cupcake pan with 8 liners.
Stir together melted butter, sugar, and cocoa. Stir in eggs, vanilla extract, coffee or water, and salt. Carefully stir in flour. (The coffee just adds a richness to the brownies, but you can use water if you prefer.)
Place about 1/4 cup of batter in each cupcake liner. You’ll have to scrape the bowl with a spatula and get every drop of batter, but you’ll get 8 cupcakes.
Bake for 16-18 minutes, until a toothpick comes out clean from right along the edge of the liner. (The toothpick will still be full of batter from the center, but you don’t want that clean or your brownie will be dry.) Cool completely before frosting.
Make frosting: beat butter and salt until smooth. Slowly mix in powdered sugar until crumbly. Add extracts and 2 tablespoons of heavy cream. Beat until smooth, adding more cream as needed to get the consistency desired. Stir in 1/2 cup mini chocolate chips. You want the frosting stiff enough to hold up on it’s own. Frost cupcakes as desired. I used an ice cream scoop to scoop a 1/4 cup frosting onto each cupcake. If you wish, melt the remaining mini chocolate chips in a microwave safe bowl (in 30 second increments, stirring between each) and then drizzle over cupcakes.
Store in refrigerator loosely covered, serve at room temperature.