Blitzkuchen - Easy German Lightning Cake

Ingredients

• All purpose flour - Provides the base structure for both the crunchy streusel and light cake.
• Brown sugar - Adds a caramel flavor. Both light and dark brown sugar work well in the streusel, or you could substitute granulated sugar.
• Ground cinnamon - Adds a warm flavor to both the streusel and the cake.
• Unsalted butter - Allow the butter for both the streusel and coffee cake to soften to room temperature, so they can easily be mixed.
• Granulated sugar - Sweetens the cake and helps whip air into the butter. I don't recommend using brown sugar in the cake, which could add too much moisture.
• Eggs - Binds the cake batter ingredients together and helps the cake rise in the oven.
• Vanilla extract - Enhances the flavors of the other ingredients.
• Milk - Both dairy and non-dairy milk work well. I usually use oat milk or almond milk.
• Baking powder and baking soda - Act as leavening agents to help the cake rise as it bakes.
• Salt - I recommend using non-iodized table salt or fine sea salt for the best flavor, not kosher salt.

How to Make this Recipe

Below is the process to make this recipe. For the full step-by-step directions and ingredient quantities, scroll down to the recipe card at the bottom of this post.

1. Mix the streusel ingredients in a bowl until it looks like wet sand.

2. Beat the softened butter and sugar until it is pale and fluffy.

3. Add the egg and vanilla and beat the mixture until it’s well combined.

5. Mix in the flour, baking powder, baking soda, cinnamon, and salt.

7. Sprinkle the streusel on top.

4. Add the milk and mix for 30 seconds on low speed.

6. Spread the cake batter into a greased 9-inch round cake pan.

8. Bake for about 30 to 35 minutes.

Recipe Test Notes:

I tested this cake several times before perfecting it!

At first the cake turned out gummy and dense. There was too much liquid in the batter, so I reduced the amount of milk. And I added baking soda to get a light and fluffy texture.

Also the brown sugar streusel was far too moist and thick during an early attempt. I added more flour and omitted vanilla extract, to get the perfect crumbly texture.

Recipe Tips

• Large Cake: To shorten the bake time on this cake, use a larger baking pan like a 9-inch by 13-inch size. Your cake will be a lot thinner, but you can cut the baking time in half. 
• Softened Butter: Make sure your butter is softened to room temperature. If it's melted or cold, it won't create the right texture in the streusel and cake.
• Mix Streusel by Hand: I find it a lot easier to mix the streusel with my hands rather than with a spoon.
• Don't Overmix Batter: Don't overmix the cake batter, or else it could end up dense. Once you add the dry ingredients, gently mix the batter just until you no longer see pockets of dry flour.

Variations

• Nut Topping: Instead of the streusel topping, you can top it with sliced almonds like Butterkuchen. Or make almond streusel like my almond cherry coffee cake.
• Powdered Sugar Topping: Leave off the crunchy topping completely and dust powdered sugar on top once it comes out of the oven, like Marmorkuchen. 
• Spices: You can add other warm spices to the streusel and cake like ground cloves, allspice, or cardamom.

Equipment

• 9-inch cake pan - I recommend using a springform pan or a cake pan with a removable bottom, so it's easy to get your baked cake out of the pan.
• Mixing Bowl
• measuring cups and spoons
• hand mixer - Use either an electric hand mixer or a stand mixer with the paddle attachment to beat the butter & sugar with the other ingredients.
• Large Spoon or Spatula

Storage

• Room Temperature: Store leftover cake wrapped in plastic cling wrap or under a cake dome at room temperature for up to 3 days.
• Fridge: I don't recommend storing the cake in the fridge, since the moisture can cause the streusel to become soft.
• Freezer: Wrap the cake or individual slices tightly in plastic cling wrap, then in aluminum foil. Store in the freezer for up to 3 months.

Frequently Asked Questions

Cake I freeze this cake?

Yes, you can freeze Blitzkuchen. Allow your baked cake to cool completely, then wrap it tightly in plastic wrap, then in aluminum foil. Freeze for up to 3 months, and allow the cake to defrost overnight at room temperature.

What makes a cake fluffy versus dense?

The temperature of the butter has a huge effect on the cake’s texture. Softened butter creates a soft, fluffy cake, while melted butter creates a dense, compact cake.
Other factors like the amount of moisture and leavening agents in the batter also affect texture.

Should you beat eggs before adding them to cake batter?

Since this cake uses baking powder & baking soda as the main leavening agents, not whipped egg whites, you don’t need to beat the eggs prior to mixing them into the cake batter.