Over a double boiler, melt together chocolate and butter until just melted. If you don’t have an official double boiler, you can place a mixing bowl over simmering water and add the chocolate and butter to the mixing bowl.

In a separate bowl, whisk together egg, sugar, food coloring, vinegar, and a pinch of salt.

When chocolate is melted, slowly whisk it into the egg mixture until well combined.

Stir in flour.

Butter four small (7 ounce) baking ramekins or you can use cupcake tins. Sprinkle the ramekins or tins with cocoa powder until covered. Tap out extra cocoa powder so there is only a light layer covering the surface.

Divide cake batter between ramekins or cupcake tins.

When ready to bake cakes, preheat oven to 350 degrees Fahrenheit.

Bake cakes for 14 minutes or until the cakes are starting to crack on the surface.

Remove cakes from oven and let cool for a few minutes.

Run a butter knife around the edges of the cakes and carefully invert them on some aluminum foil. Tap on the bottom gently and remove the baking dish.

Carefully flip the cake back over on your serving plate and sprinkle with powdered sugar. Serve immediately!