01 - Preheat the oven to 350°F. Grease and line a 9-inch round cake pan with parchment paper.
02 - In a large bowl, whisk together flour, baking powder, salt, cinnamon, and nutmeg until well combined.
03 - Add cold butter cubes to the flour mixture. Rub with fingertips until the mixture resembles coarse breadcrumbs.
04 - Stir in 3/4 cup sugar and the sliced apples, tossing to coat the apples evenly with the mixture.
05 - In a small bowl, beat eggs, milk, and vanilla extract together until combined.
06 - Pour the wet mixture into the dry ingredients. Fold gently until just combined, being careful not to overmix.
07 - Transfer the batter to the prepared pan, smoothing the top evenly. Sprinkle with 2 tablespoons sugar.
08 - Bake for 45 to 50 minutes, or until the cake is golden and a skewer inserted in the center comes out clean.
09 - While the cake bakes, heat milk and cream in a saucepan over medium heat until just simmering.
10 - In a bowl, whisk egg yolks, sugar, and cornstarch until the mixture is pale and smooth.
11 - Gradually pour the hot milk mixture into the yolks while whisking constantly to prevent curdling.
12 - Return the mixture to the saucepan and cook over low heat, stirring constantly until thickened. Do not let it boil.
13 - Remove from heat and stir in vanilla extract. Set aside to cool slightly.
14 - Allow the cake to cool slightly before serving warm slices with generous spoonfuls of vanilla custard.