Creating an amazing Coffee Cake is simple if you follow these instructions:

1. Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan.
2. In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
3. Add eggs one at a time, mixing well after each addition. Then stir in the vanilla extract.
4. In a separate bowl, combine the all-purpose flour, baking powder, baking soda, and salt.
5. Gradually add the dry ingredients to the wet mixture, alternating with sour cream. Begin and end with the dry ingredients.
6. Mix until just combined; be careful not to overmix.
7. In a small bowl, prepare the streusel topping by combining brown sugar, cinnamon, and chopped nuts (if using).
8. Pour half of the batter into the prepared pan and spread it evenly. Sprinkle half of the streusel mixture on top.
9. Add the remaining batter, smoothing it out again. Finally, top with the rest of the streusel mixture.
10. Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
11. Once baked, let the cake cool in the pan for about 10 minutes. Then transfer to a wire rack to cool completely.

With these straightforward steps, you’ll be set to impress!