Preheat oven to 375° F. Butter and flour a 9-inch springform pan set it aside.
In a large mixing bowl whisk together flour, baking powder, salt, ginger, nutmeg, allspice and ¼ teaspoon cinnamon.
Add butter and work it into the mixture with a pastry cutter or forks, until it resembles fine crumbs.
Stir in 1 cup of sugar.
Peel apples, cut into quarters, and remove core. Cut apple quarters into ¼ inch or thinner slices. If you have an apple/peeler/corer slicer use that and cut the rings into quarters.
Mix apples into the flour mixture until apples are evenly coated.
Using a 2 or 4 cup measuring cup measure milk then add eggs and vanilla and whisk until combined.
Add milk mixture to the flour/apple mixture and fold gently to combine. Batter will be lumpy, do not overmix.
Pour batter into the prepared baking dish and spread into an even layer.
In a small dish combine 2 tablespoons of sugar and ½ teaspoon cinnamon. Sprinkle mixture over the top of the cake.
Bake until golden and a toothpick inserted into the center comes out clean, about 45-50 minutes.
Cool on a wire rack for 10 minutes then remove the ring from the springform pan. Allow cake to cool completely.
Custard Sauce
In a medium mixing bowl and beat egg yolks and sugar on medium high until pale and fluffy, about 1-2 minutes.
In a medium saucepan, heat milk over medium high heat until just beginning to boil.
Immediately, reduce heat to medium-low heat.
Add about ½ cup of the hot milk to the egg yolks while whisking. Don't skip this step or you will have lumps of egg yolks in your milk.
Add egg yolk mixture to the saucepan while whisking continuously.
Cook, while stirring constantly, until custard is thickened and it coats the back of the spoon, about 3 - 4 minutes.
Immediately pour into a small bowl or pitcher and stir in the vanilla extract.
Drizzle warm custard on top of the cake just before serving.