Sour Cream Apple Coffee Cake with Crunchy Streusel Topping

1.Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan or line it with parchment paper.

2.In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and ground cinnamon. Set aside.

3.In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes.

4.Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and sour cream until fully combined.

5.Gradually add the dry ingredients to the wet mixture, mixing just until combined. Do not overmix. Fold in the diced apples gently.

6.Pour the batter into the prepared baking pan, spreading it evenly.

7.In a separate bowl, prepare the streusel topping by combining the brown sugar, rolled oats, chopped nuts, and melted butter. Mix until crumbly.

8.Sprinkle the streusel topping evenly over the batter in the baking pan.

9.Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.

10.Allow the cake to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.