Preheat oven to 350º F/ 180º C. Grease very well two 7 inch/ 18 cm round pans and line them with circles of parchment paper. Grease the paper too.

In a bowl combine the almond flour, coconut flour, baking powder and salt. Whisk gently to combine.

In a large mixing bowl beat eggs and erythritol for 4-5 minutes until the mixture becomes pale and doubles its volume.

Add vanilla extract and beat shortly to combine.

Using a rubber spatula gradually add the dry ingredients. Mix gently until absorbed.

Pour the batter into the prepared pans. Bake for about 25 minutes or until a toothpick inserted in the centre comes out clean.

Let the bases sit for 15 minutes in the pans and then remove them carefully by running a knife around the edges and inverting on a rack. The texture will be crumbly but that is not a problem for Tiramisu.

Let the layers cool to room temperature before assembling the cake.

In a large mixing bowl using an electric mixer beat the mascarpone with the erythritol for few seconds until fluffy.

In another bowl whip the cold cream until fluffy but still creamy.

Little by little add the cream to the mascarpone, folding it gently with a rubber spatula.

Combine the coffee with the rum extract and mix.

Place one layer in a spring form pan lined with a circle of parchment paper or on a serving plate with a cake ring. Use a tablespoon to soak it all around with half of the coffee.

Spread half of the frosting on top.

Place the second layer over the frosting and soak it with the rest of the coffee. Cover with the remaining mascarpone mixture. Smooth it out with a spatula.

Sprinkle some cocoa powder on top.

Close the spring form pan or the cake ring and cover with aluminium foil. Place the Tiramisu in the fridge for at least 4 hours.

Sprinkle more cocoa powder on top before serving.