Simple Pleasures Irish Apple Cake Recipe

Preheat your oven to 350°F. Grease a 9-inch springform pan. Before starting the cake, make the custard sauce in advance.
Heat milk until it simmers. While that's happening, whisk together egg yolks and sugar until well mixed.
Slowly mix a bit of the hot milk into the eggs, whisking continuously.
Transfer the egg mixture back to the hot milk, cook over medium heat, stirring until it coats a spoon.
Add vanilla, then strain the custard through a sieve into a jar or bowl. Cover with plastic wrap and chill it in the refrigerator.
Mix cold butter bits with flour, sugar, and oats until it's crumbly. Pop it in the refrigerator for later.
Cream together butter and sugar until it's light and fluffy. Add eggs one at a time.
Whisk together flour, baking powder, cinnamon, and salt. Gently fold these dry ingredients into the butter and sugar mixture along with milk or cream.
Spoon the batter into your prepared pan and spread it evenly. Top it with sliced apples, and then sprinkle on the streusel topping. No need to be perfect; just make it even.
Bake for about 50 minutes to an hour until the top is lightly browned. Check with a toothpick – it should come out clean without wet batter sticking to it.
Let it cool a bit in the pan before removing. Dust with confectioner’s sugar before serving.