Delicious sheet cakes with crunchy streusel topping are so popular in the Czech Republic, Germany, and Poland; in fact in the whole of Central Europe! On sweet pastries, the sprinkles form the final layer that takes the dish to the next level. In this simple recipe, I will show you how we make the perfect topping in the Czech Republic.
Using a knife, carefully cut the butter into small cubes and add them to the dry ingredients.
Work all the ingredients together using your fingers until you have a sand-like mixture with firm, irregular lumps.
Makes a batch of streusel for a large coffee cake baked in a pan of size 16x12 inches (40x30 cm). Use two-thirds of that amount for a 9x13-inch (23x33 cm) pan.
If you prepare the streusel in advance, put it in a bowl in the fridge to stay chilled. Sprinkle streusel on the cake just before baking.
Do you want a crunchy topping that stays that way the next day? Add an egg yolk to it when preparing. Then you'll need to add more flour and sugar to make the crumbs less dense.
If you have a leftover topping, store it in an airtight container in the fridge. It will keep for about a week.
Streusel topping freezes perfectly. Spread it in a large bag in a thin layer and leave it in the freezer for about 20 minutes. Afterward, shake the crumbly topping in a bag or a freezer-safe container together and let it freeze completely.