Preheat your oven to 350°F (175°C).
Grease and line an 8x8-inch baking dish with parchment paper.
In a large bowl, whisk together the flour, granulated sugar, baking powder, baking soda, salt, and ground cinnamon.
In another bowl, mix the mashed bananas, dairy-free yogurt, melted coconut oil, vanilla extract, and plant-based milk until smooth.
Add the wet ingredients to the dry ingredients, mixing until just combined.
Pour the batter into the prepared baking dish and spread it evenly.
Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes.