Preheat your oven to 350°F (175°C) and line a 9-inch round cake pan with parchment paper or non-stick spray.

In a large mixing bowl, whisk together all-purpose flour, baking powder, baking soda, salt, and sugar until combined.

Create a well in the center and add melted coconut oil, mashed banana, vanilla extract, apple cider vinegar, and dairy-free milk. Mix until just combined.

Gently fold in ½ cup of blueberries into the batter.

Pour the batter into the prepared pan and smooth it out. Arrange sliced banana and remaining blueberries on top.

Bake for 45-55 minutes, checking for doneness with a toothpick.

Let the cake cool in the pan for 10-15 minutes, then transfer to a wire rack to cool completely.