Blend the wet ingredients

• Add the black beans, eggs, melted butter, sugar and vanilla to the blender.
• Blend on high speed until completely smooth.

Add the dry ingredients

• Add the cocoa powder, baking powder and baking soda.
• Blend again until fully combined, scraping down the sides.

Bake the cake

• Pour the batter into a greased cake pan.
• Bake at 175 °C for 35 minutes, until a skewer comes out clean.

Cool and unmould

• Let the cake rest in the pan for 5 minutes.
• Flip it out onto a cooling rack and let it cool completely.

Frost and serve

• Spread the chocolate buttercream frosting over the cooled cake.
• Slice and serve.