5 min chocolate brownie (low cal)

So I found this low calorie brownie recipe on Reddit and tweaked it a bit. It's delicious and less than 100 calories!

Ingredients:
1 egg (or egg white for lower calories)
2 tbsp cocoa powder
2 tablespoons sugar substitute of choice (I used Sweet & Low)
Pinch salt
1 tbsp heavy cream/milk ( I used greek yogurt with some water instead)
1/2 tsp vanilla extract
1/4 tsp baking powder

Directions:
Spray the mug with cooking spray.
In a small bowl, beat the egg. Set aside. In a separate, slightly larger bowl, mix cocoa powder, sugar substitute, and salt. Add cream/milk/yogurt, vanilla, and egg to the dry ingredients. Mix well. Add baking powder and mix again.
Firmly tap the mug on the counter to release any large air bubbles.
Cook for around 1 minute 20 seconds, depending on your microwave. The top of the cake should be solid. Flip cake onto a plate to cool.
Top with whipped cream or berries if desired.

Bon appetit!