Mum’s Irish Apple cake . This classic Irish Apple Cake may seem humble but it is a diamond in the rough. Somewhere a cross between an American coffee cake and an apple pie, this cake is one of my mum's best Irish recipes. I am so happy to share this with you as I know it will be an instant family favorite. An Irish Apple Cake is technically not a cake at all. Traditional Irish Apple Cake Recipe with Custard Sauce. Tart, crisp apples suspended in tender vanilla spice cake with a crunchy sugar topping and creamy vanilla custard sauce. You can have Mum’s Irish Apple cake using 16 ingredients and 5 steps. Here is how you cook that. Ingredients of Mum’s Irish Apple cake You need of For the strudel topping. You need 3/4 cup of flour. Prepare 1/4 cup of oats. You need 1/2 cup of brown sugar. It's 6 tablespoon of cold butter. It's of Cake part. You need 1/2 cup of butter. You need 1/2 cup of sugar. ...