Step 1

In a 12-ounce (or larger) mug, whisk together the milk, olive oil, and sugar. Whisk in the flour until smooth, then whisk in the oats, pecans, baking powder, salt, and cinnamon and nutmeg, if using.

Step 2

Dollop the Nutella on top and push in gently so it is partially submerged in the cake batter.

Step 3

Microwave on HIGH for 30 seconds, and then in 15-second bursts until the top looks dry and cooked and springs back when pressed with a finger.

Step 4

→ On microwave power: My microwave is 700 watts and it took between 70 and 90 seconds total for the cake to be done, depending on the batch. Times will vary in microwave ovens of different powers. So I recommend a conservative approach of microwaving for 30 seconds and then in short bursts, checking between each.

Step 5

Let stand at least 5 minutes before eating, as the cake and Nutella center will be quite hot. Top with additional Nutella if feeling indulgent!