Spiced Coffee Cake with Walnuts

Ingredients:

Streusel

• 0.5 cup granulated sugar
• 1/3 cup dark brown sugar
• 1 cup toasted walnuts, chopped
• 2 tbsp. premium flour
• 1 tbsp vanilla extract
• 1 teaspoon ground cinnamon
• 2 tablespoons unsalted butter, melted

Pie

• 110g unsalted butter, room temperature, plus extra for greasing the pan
• 2 cups premium flour
• 1 teaspoon of baking soda
• 1 teaspoon apple pie spice
• 0.5 tsp fine salt
• 1 cup granulated sugar
• 2 large eggs, room temperature
• 1.5 tsp vanilla extract
• 1 cup sour cream

Preparation:

1. In a medium bowl, combine the white and dark brown sugars, walnuts, flour, vanilla extract, and cinnamon. Add the butter and mix until moist, coarse crumbs form; set aside.
2. Preheat oven to 175°C. Line the bottom of an 8-inch square baking pan with parchment paper; grease the paper and the sides of the pan with butter.
   
   
   When measuring flour, spoon it into a dry measuring cup and remove any excess. Scooping flour directly from the bag with a measuring cup will compact it, resulting in dry baked goods.
3. Pie:
   
   Sift the flour, baking soda, cake spices, and salt into a medium bowl. In a large bowl, beat the butter and sugar with a mixer on medium speed until light and fluffy, about 5 minutes. Add the eggs one at a time, beating well after each addition; stir in the vanilla extract. Add the flour mixture in three additions, alternating with the sour cream, beginning and ending with the flour and mixing well after each addition.
4. Spoon 2/3 of the batter into the prepared pan and sprinkle with half the streusel. Top with the remaining batter and streusel. Bake until a toothpick inserted into the center of the cake comes out clean and the top is golden brown, about 1 hour and 10 minutes.
5. Cool the cake in the pan on a wire rack for 20 minutes. Remove it from the pan and invert it with the streusel facing up. Let it cool completely.