in a saucepan, melt the vegan butter over medium-high heat until it starts to boil. continue boiling for a few minutes until it reaches a brown color and a nutty aroma. remove from heat and stir in the almond butter and miso paste until smooth and combined.

in a large bowl, combine the brown butter mixture, mashed banana, coconut sugar, and vanilla bean paste or extract. mix well until smooth.

add the oat flour, almond flour, baking powder, and baking soda to the wet ingredients. stir until just combined, being careful not to overmix.

preheat the oven to 350°F (175°C). line an 8x8-inch baking pan with parchment paper or lightly grease it.

pour the batter into the prepared pan, spreading it evenly. bake for 35 minutes, or until a toothpick inserted into the center of the cake comes out clean.

let the cake cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.

while the cake cools, prepare the frosting. in a food processor or with an electric mixer, blend the vegan cream cheese, maple syrup, vanilla bean paste, and cinnamon until smooth.

once the cake is completely cooled, frost it with the cream cheese mixture.