Coffee Cake with Cinnamon Streusel

👨‍🍳 Method

To assemble

1. 1
   Preheat the oven to 175°C (345°F) and grease Round pan of 24 cm.

   ⚙ Preheating the OvenOven

   💡Put things in the oven only once it's reached temperature, after the heating light has gone off: an oven that hasn't reached temperature changes baking times, and the bake burns outside or stays underbaked.
2. 2
   Whip the soft butter with the sugar 3 minutes, until pale and fluffy.

   ⚙ WhippingBowlHand mixerorStand mixerorWhisk

   💡Cream the butter soft, at room temperature: cold butter doesn't take in air, and melted butter doesn't hold it.
3. 3
   Add the eggs one at a time, beating after each until absorbed.

   💡One egg at a time, and only when the previous one is absorbed: that way the emulsion holds and the batter doesn't split into curds.
4. 4
   Add the sour cream, coffee and vanilla and mix.
5. 5
   Add the flour, baking powder, baking soda and salt and Fold gently, just until no dry flour remains.

   ⚙ FoldingSilicone spatula

   💡Fold with a spatula, in broad strokes from the bottom up, and stop when there's no dry flour: vigorous mixing of a batter with flour develops gluten.
6. 6
   Pour into the pan.

   Baking pan
7. 7
   Mix the flour, sugar and cinnamon in a bowl.

   Bowl
8. 8
   Add the cold butter and rub it into the dry mixture with your fingertips, until coarse crumbs form.
9. 9
   Cover the batter with the crumbs until it is completely covered.
10. 10
    Bake 35–40 minutes, until a toothpick inserted in the center comes out clean.

    ⚙ BakingOvenBaking pan

    💡Check by the cue (until…), not just the clock: every oven bakes a little differently.
11. 11
    Let cool completely before slicing.