In a microwave-safe bowl, mash your banana. Whisk in the egg, milk, and honey or maple syrup (if using). Mix to combine.
Mix in the oats and baking powder until combined.
Gently fold in the diced strawberries.
Microwave the mixture on high for about 3-4 minutes, or until the oat cake is set and cooked through. Cooking time can vary depending on your microwave, so check it after 2.5 minute and add additional time if needed.
Allow the oat cake to cool for a minute or two before serving. It will firm up slightly as it cools.
Top with extra sliced strawberries or a dollop of yogurt if desired.
Serve and enjoy!