Step 1
Preheat the oven to 180C fan-forced (200C conventional). Grease and line a 23cm round cake tin. Set aside.
Step 2
In a medium bowl, combine the flour, almond meal, cinnamon, nutmeg and salt. Set aside.
Step 3
In the large bowl of a stand mixer fitted with a paddle attachment, cream the butter and sugar until light and pale (about 4–5 minutes). Alternatively, use hand-held electric beaters. Add the eggs, one at a time, beating well between each addition. Add the lemon zest and vanilla and mix briefly. The mixture may look a little split, but will come together.
Step 4
Remove the bowl from the stand mixer, if using. Fold the dry ingredients into the wet ingredients using a spatula and mix until just combined. Fold through the apples, then spoon the mixture into the prepared cake tin. Bake in the preheated oven for 40 minutes or until a skewer comes out clean when tested.
Step 5
Allow to cool in the tin for 10 minutes, then invert onto a cake rack to complete cooling. Place it the right way up on a serving plate and set aside.
Step 6
For the frosting, whisk together the mascarpone, maple syrup and vanilla in a bowl until just combined. Be careful not to overmix.
Step 7
Spoon the frosting onto the cake and spread using a palette knife to create a swirled effect. Drizzle over a little extra maple syrup and serve.