Preheat the oven to 340°F (170°C) and line a cupcake pan with paper liners.
In a small bowl, whisk together the cake flour, cocoa powder, salt, baking soda, and baking powder. Set aside.
In a separate bowl, mix together the sugar, mashed bananas, olive oil, almond milk, apple cider vinegar, and vanilla extract.
Add the dry ingredients and mix together until just combined.
Pour the batter into the cupcake liners and bake for 18-20 minutes, or until a toothpick inserted comes out clean. Let them cool in the pan for a couple minutes before transferring them to a wire rack to cool completely.
Frosting
In a bowl, beat the vegan butter until light and fluffy. Add the cocoa powder and beat again.
Add the powdered sugar ½ cup at a time and continue to beat until creamy.
Add 1 teaspoon of almond milk and beat. If you like your frosting thinner, add another teaspoon of almond milk.
Frost each cooled cupcake using a piping bag or a knife. Garnish with fresh berries or sprinkles.