Classic Irish Apple Cake

by Haley // February 14, 2023

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This simple, yet flavorful cake, can be served at breakfast, afternoon tea or dessert. Irish apple cake has a crumble topping and is served with a thick custard sauce. It’s a traditional recipe that is easy to make from scratch.

custard sauce poured on top of Irish apple cake on plate.

If you were to take a coffee cake and marry it with an apple crisp, you would get this old fashioned Irish apple cake. It has a tight-knit tender crumb, layers of crisp apples and a streusel topping. It tastes delicious with the homemade custard sauce! I like using leftover sauce for my apple tarte tatin.

Table of Contents

Why this recipe works

It’s a modest recipe that has the perfect balance of flavors and textures. You can serve this crumble cake any time of day. Enjoy it for breakfast, dessert or as an afternoon snack (Irish tea cake is also a good tea time treat!) In fact, I find it tastes even better the day after it’s baked! It’s the perfect dish for St. Patrick’s Day, but you can also make it in the fall when apples are in season or even Thanksgiving!

Ingredient notes

Irish apple cake ingredients in bowls labeled with text.

Apples: I prefer Granny Smith apples for baking because they keep their crisp texture and flavor under the high heat of the oven.
Oats: Old fashioned oats, also known as rolled oats, add a chewy texture to the streusel topping. Quick oats can be used as a substitution, but I do not recommend steel cut oats as they are too tough.
Butter: The streusel requires cold butter to maintain a crisp texture. Meanwhile, the cake requires room temperature unsalted butter for easy mixing.
Flour: All purpose flour is best for this recipe, but cake flour will work too.
Baking powder: This helps the cake rise. Make sure it is fresh and not expired for best results.
Egg yolks: Custard sauce uses egg yolks for a rich flavor. I suggest separating them ahead of time and making sure no shells get in the bowl.
Milk: Custard sauce is best with whole milk for a thick and creamy texture. In a pinch, half and half or cream can be used. I do not recommend dairy-free alternatives.

Recipe variations

If you don’t have a springform pan, a 9-inch round cake pan with 2-inch tall sides or 9-inch square pan can be used in the recipe with approximately the same baking time. Be sure to grease the pans well!

Try different sauces for this apple cake. A salted caramel sauce would taste delicious or you can drizzle on a simple icing. Whisk together 1 cup confectioners’ sugar with 2 Tablespoons milk and 1 teaspoon vanilla. You can also serve the cake with vanilla ice cream or whipped cream.

The crumble topping uses granulated sugar, but brown sugar is a good substitute if you want more flavor. It’s what I like to use in my apple crisp topping. A 1/4 cup chopped nuts such as pecans or walnuts are also a nice addition to the streusel.

Another way to spice up the recipe is to add 1/2 teaspoon nutmeg to the dry ingredients. You can also mix in 1/2 cup raisins, dried currants or chopped nuts into the batter. Use any leftover dried currants in my Irish soda bread muffins.

How to make Irish apple cake

Prepare the streusel: Whisk together the flour, oats, sugar and salt. Cut the cold butter into the dry ingredients using a pastry cutter or two forks. Set aside in the refrigerator.
Whisk together the dry ingredients. Set aside.
Beat butter and sugar until creamy. Mix in eggs on at a time, then add the vanilla and milk. Mix until combined.
Add dry ingredients to the wet ingredients. Stir just until incorporated.

photo collage demonstrating how to layer apple cake with streusel and make custard sauce in saucepan.

Assemble and bake: Transfer batter to a greased 9-inch springform pan. Layer apples on top. Sprinkle streusel over apples.
Bake cake at 350° F for one hour or until a toothpick inserted in the center comes out with little to no crumbs. Cool completely.
Make the custard sauce. Whisk together egg yolks, sugar and vanilla. Set aside. Heat milk in a saucepan until scalding hot. Add about 1/2 cup hot milk to egg yolks to temper them.
Transfer mixture back to the saucepan, whisking constantly. Cook custard over medium heat until thickened, about 4 minutes. Transfer to a bowl and serve with cake.

Expert tips

Weigh your ingredients for accurate measuring. If you don’t have a kitchen scale, be sure to spoon your flour into a measuring cup and level it with a knife.

Use room temperature ingredients for cake batter. The ingredients will mix more easily and create a consistent and smooth batter. However, for the streusel, use cold butter and cut it into the flour with a pastry cutter or two forks. This will ensure a crumbly texture.

Do not over-mix when combining the wet ingredients with the dry ingredients for the cake. Mixing just until the last of the flour disappears guarantees a tender crumb.

For the custard sauce, heat the milk just until it simmers at the edges of the pan (don’t bring to a boil). Then be sure to temper the egg yolks by whisking them with 1/2 cup hot milk. This will prevent the eggs from curdling when you add them back to the pan.

Irish apple cake with crumble topping on a plate next to Granny Smith apples.

Storage and make ahead tips

Irish apple cake will keep at room temperature for up to 2 days or in the refrigerator for up to 5 days. After the cake has cooled, cover it with plastic wrap or aluminum foil to prevent it from drying out.

It can also be frozen for up to 2 months. Wrap the cooled cake in plastic wrap, then place it in an airtight container or bag to prevent freezer burn. Defrost in the refrigerator before bringing to room temperature and serving.

Custard sauce may be kept in an airtight container in the refrigerator for up to 5 days. To reheat, place in a double boiler over simmering water and cook until warm or reheat in the microwave on 50% power level (stir frequently). Custard sauce does not freeze well.

Frequently Asked Questions

Why is streusel not crumbly?

It was likely over-mixed or the butter was too warm. Be sure to use cold butter. Remember your body heat from your hands can warm the butter when mixing, which is why I recommend a pastry cutter or two forks.

Why is the custard not thickening?

It’s either not cooked long enough or there is too much milk. Try whisking in 1 Tablespoon of cornstarch to thicken the sauce.

What is the history of Irish apple cake?

Traditionally, the cakes were cooked in a cast iron skillet over a stove before ovens were commonplace in the home. Crab apple trees are abundant in Ireland making the fruit a popular ingredient in baking.