Step 1

Combine cocoa powder, flour, sugar, and salt in a 10- to 12-ounce microwave-safe coffee mug. Using a fork, stir until well combined. Add the milk, oil, and vanilla. Stir just until the dry ingredients are almost combined. Add the chocolate chips, and stir until well combined. Sprinkle a few more chocolate chips on top, if desired.

Step 2

Place the mug in the microwave and microwave on high power for 1 minute. The brownie should have risen and still appear moist in spots on the top. Continue cooking in 10-second intervals if the batter still looks raw. Let the brownie cool for a few minutes before serving with ice cream.