Step 1

In a small bowl whisk together the oat flour (and protein powder if using), sugar, baking powder, and salt until combined.

Step 2

Pour the oil, vinegar, and vanilla in three different spots on top of the dry mix. (see video in post)

Step 3

Pour milk over the top and gently stir.If desired, mix in any add-ins.

Step 4

Pour the batter into a greased tall/deep mug or 8-ounce ramekin. (If adding plant-based protein powder, the batter will be thicker. If needed, use the back of a spoon to gently press the mixture down into the mug.

Step 5

Microwave on HIGH in 3 intervals of 30 seconds each time, check to see if the cake is firm. The top should be firm to the touch once cooked. If not, cook for 15-20 seconds longer (the total time depends on microwave power). Remove from the microwave and let it cool a minute.

Step 6

Top mug cake with optional toppings and dig in with a spoon or, if desired, flip over onto a plate and add toppings.