Preheat the oven to 180C/160C fan/gas 4. Line a fairy-cake tray with paper cases.
Put the flour, ground almonds and baking powder in a bowl and whisk to combine them thoroughly.
Beat the butter with an electric whisk in a separate bowl or in a stand mixer for 4-5 minutes until it’s very fluffy and white. Add a spoonful of the flour and almonds to the butter, then an egg, whisking well in between each addition. Add the remaining egg, then more flour and almonds, again whisking well.
Fold in the remaining flour and almonds, then add the maple syrup, lemon zest and juice and the almond extract (optional). The mixture should be fairly wet and drop from a spoon easily.
Divide the mixture among the cases and bake for 15-20 minutes until well risen and golden brown. Remove them from the oven, take the cakes out of the tray and place them on a cooling rack.
Mix the mascarpone with the maple syrup and a little lime juice. When the cakes are cool, decorate with the mascarpone and lemon/lime zest.
