Step 1

Spray a large microwave-safe mug with nonstick spray. Add both types of flour, sweetener, baking powder, cinnamon, and salt. Mix well.

Step 2

Add all remaining ingredients except blueberries. Stir until uniform.

Step 3

Gently fold in blueberries.

Step 4

Microwave for 2 1/2 minutes, or until set.

Step 5

Immediately run a knife along the edges to help separate the cake from the mug.

Step 6

Gently shake mug to release muffin, and plate, right side up.

Step 7

Let cool completely, about 25 minutes. (This step is a must for best texture.)