Step 1

Spray mugs (make sure they are at least 12 oz in size) with cooking spray. Set aside.

Step 2

In a small bowl or 4 cup glass measure, whisk together the egg and oil.

Step 3

Whisk in milk, vanilla, and sugar.

Step 4

Add flour and whisk until batter is smooth.

Step 5

Pour equally, into prepared mugs.

Step 6

Microwave them one at a time for 1 1/2 minutes on HIGH.

Step 7

Test the cake to see if it springs back, if not, put in the microwave for 10 more seconds.

Step 8

Repeat with second mug.

Step 9

Allow cakes to cool completely. Serve with whipped topping, if desired.