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 and rub with fingertips until coarse breadcrumbs form.
04 - Stir in 3/4 cup sugar and sliced apples, tossing thoroughly to coat evenly.
05 - In a small bowl, beat eggs, milk, and vanilla extract until smooth.
06 - Pour the wet mixture into the dry ingredients and fold gently until just combined. Avoid overmixing.
07 - Transfer batter to the prepared pan, smoothing the surface evenly. Sprinkle with remaining 2 tablespoons sugar.
08 - Bake for 45 to 50 minutes until 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 - Whisk egg yolks, sugar, and cornstarch in a bowl until pale and smooth.
11 - Gradually pour the hot milk mixture into the yolks while whisking constantly to prevent curdling.
12 - Return mixture to the saucepan and cook over low heat, stirring constantly until thickened. Do not 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.