Recipe as written is for a 2-layer cake. If you'd like a 4 tiered cake, make 2 batches of cakes. Or double the recipe and use 4, 4" round cake pans.
Preheat oven to 350ºF and line 2, 4 inch by 2 inch cake pans with cut out parchment paper, grease edges with coconut oil or butter; set aside.
Make batter: In a medium bowl combine mashed banana, egg, oil, milk and vanilla extract. Add in oat flour, baking soda, baking powder, pinch of salt and a dash of cinnamon. Stir until batter is smooth.
Bake: Evenly distribute batter into prepared pans, filling about ½ way full. Bake cakes for 18-22 minutes, OR until inserted toothpick in center comes out clean.
Cool: Allow cakes to rest in pan for 10 minutes before flipping onto cooling rack. Make sure cakes are cooled completely before frosting. You can place in fridge to speed things up.
Make coconut whipped cream frosting: Do not shake canned coconut milk before opening. Carefully scoop out cream and discard liquid. Using a chilled metal bowl (if possible), place coconut cream in bowl and whip with electric mixer until light and fluffy. You can use food coloring here if you'd like, a hint of maple syrup, or leave plain. Place whipped coconut cream in fridge until you're ready to frost.
Frost cake: Place cake on cake stand or plate, add a couple of tablespoons of whipped cream on first layer, top with second layer and frost rest of cake. Chill cake in between frosting layers if doing a 4 tier cake.
Chill & Serve: Be sure to keep cake chilled right up until serving, since coconut cream will melt at room temperature. Note: If making 4 layers, secure cake with wooden dowel (cut skewer to size of stacked cakes before frosting).
