Streusel

Streusel is a sweet, crumbly topping made from flour, butter and sugar. You scatter it over coffee cake, muffins, pies and fruit bakes before they go in the oven, and it bakes into crisp, golden clumps. It is close to the topping on a British crumble, but streusel usually has more butter, so it forms bigger, crunchier clusters.

How to do it

The basic ratio is equal weights of flour, butter and sugar.

1. Mix 100 g (¾ cup) flour, 100 g (½ cup packed) brown sugar and a pinch of salt. Add ½ teaspoon cinnamon if you like.
2. Add 100 g (7 tablespoons) butter. Use cold butter and rub it in for fine crumbs, or melted butter stirred in with a fork for large clumps.
3. Squeeze handfuls together and break them into pieces of different sizes, from peas to small marbles.
4. Chill for 15 to 30 minutes so it holds its shape in the oven.
5. Scatter it over the batter or fruit and bake as the recipe says.

How to tell it is done

Baked streusel is golden brown and crisp at the edges of each clump. It should not look pale or sandy. When it cools, the pieces are crunchy on the outside and a little tender inside.

How to store it

Unbaked streusel keeps in a covered container in the fridge for up to a week, or in the freezer for 3 months. Use it straight from frozen.

Common mistakes

• Too little butter. The topping stays dry and powdery.
• Using it warm. Soft streusel melts into the batter and sinks.
• Spreading it in a thick, even layer. Uneven clumps bake crisper and look better.
• Covering a batter that is too thin. Heavy streusel sinks. Use less, or let the cake bake for 10 minutes before adding it.

In recipes

Recipes may call it "crumb topping" or "crumble topping". Oats, chopped nuts or cinnamon are common additions. Swap a quarter of the flour for oats or nuts.

Where it comes from

Streusel is German for "something scattered". It is a classic topping on German and Central European sheet cakes.