Ina's Outrageous Brownies

2 sticks unsalted butter
1 1/2 c. semisweet chocolate chips
3 oz. unsweetened chocolate
3 extra-large eggs
1 1/2 tbsp. instant coffee powder
1 tbsp. real vanilla extract
1 c. and 2 tbsp. sugar
1/2 c. and 2 tbsp. flour, divided
1 1/2 tsp. baking powder
1/2 tsp. salt
1 1/2 c. chips (milk chocolate, dark chocolate, white chocolate, or butterscotch)

Preheat oven to 350°F. Grease and flour a 9- x 13-inch metal pan.

Melt together butter, semisweet chocolate chips, and unsweetened chocolate in double boiler. Cool slightly. Stir together eggs, instant coffee, vanilla, and sugar. Stir in warm chocolate mixture and cool to room temperature.

Stir together 1/2 c. flour, baking powder, and salt. Add to cooled chocolate mixture. Toss chocolate chips with 2 tbsp. flour to coat, then add to chocolate batter. Pour into prepared pan.

Bake for about 30 minutes, or until tester comes out clean. Halfway through baking, rap pan against oven shelf to allow air to escape from between pan and brownie dough. Do not overbake! Cool thoroughly, refrigerate well, and cut into squares.