01 -
Leave the butter, eggs, sour cream, and milk out on the counter for about an hour to reach room temperature. Stir the coffee grounds into the milk so it has time to soak while you wait.
02 -
In a medium-size bowl, melt the butter, then stir in the sugar, flour, cinnamon, and pistachios. Use a fork to mix until small chunks form.
03 -
Turn your oven on to 350°F (175°C). Coat a 9-inch cake pan with butter, line it with crunched-up parchment paper, and make sure it extends up the edges for easy lifting later on.
04 -
In a smaller bowl, whisk salt, baking powder, and flour together until combined.
05 -
Using a hand or stand mixer, beat the softened butter with the sugar for 3-4 minutes until it looks pale and fluffy.
06 -
Mix in the eggs and vanilla extract on medium speed for about a minute, making sure it all blends nicely.
07 -
Gently fold half of the dry ingredients into the butter mix. Pour in the coffee-soaked milk and sour cream, stir lightly, then finish by folding in the rest of the dry ingredients.
08 -
Pour half the batter into the cake pan, spread a third of the streusel over it, then add the rest of the batter. Put the leftover streusel on top and bake for 40-50 minutes. It's done when a toothpick comes out clean.
09 -
Once the cake cools off entirely, whisk espresso and powdered sugar together until smooth, then drizzle it all over before serving.