Pre-heat the oven to 180°C/160°C/gas mark 4 and line and grease a 2 x 8 inch round cake tins.
Whisk the egg whites until stiff in a very clean bowl and set aside.
Beat the sugar with the lemon zest and butter until light and fluffy.
Add the eggs one at a time, mixing well between additions.
Add the vanilla extract.
Whisk together the flour, almonds, baking powder and salt in a separate bowl then beat into the rest of the ingredients.
Finally fold in the egg whites.
Divide the cake between the two tins.
Sprinkle the extra tablespoon of gluten-free flour over the raspberries and shake the bowl until the raspberries are well coated in the flour.
Drop 75g of raspberries into each tin, smoothing the cake batter over the top.
Bake for 50 minutes or until an inserted toothpick comes out clean.
Remove the cakes from the oven, leave in their tins for 5 minutes before inserting them out onto cooling racks.
Brush 2 tablespoons of limoncello liberally over the top surface of the cakes.