Cinnamon Coffee Cake

Instructions

1. Prepare the baking dish
   Preheat oven to 350°F (175°C). Grease a 9x13 inch baking dish or a 9-inch springform pan with butter and lightly dust with flour to prevent sticking.
2. Make the cinnamon streusel
   In a medium bowl, mix together 1/2 cup of the flour, brown sugar, and cinnamon. Cut in 1/4 cup of the butter using a pastry cutter or fork until the mixture resembles coarse crumbs. If using nuts, fold them in now. Set aside.
3. Mix dry ingredients
   In a large bowl, whisk together the remaining 1 1/2 cups flour, granulated sugar, baking powder, baking soda, and salt until well combined.
4. Prepare the wet ingredients
   In a separate bowl, beat the remaining 1/2 cup butter until creamy. Add eggs one at a time, beating well after each addition. Stir in the sour cream and vanilla extract until smooth.
5. Combine wet and dry mixtures
   Gradually fold the wet ingredients into the dry ingredients, mixing just until combined. The batter will be thick and fluffy. Be careful not to overmix.
6. Layer the cake
   Spread half of the batter into the prepared baking dish. Sprinkle with one-third of the streusel mixture. Carefully spread the remaining batter over the streusel layer, then top with the remaining streusel.
7. Bake the cake
   Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean. The top should be golden brown and slightly crisp.
8. Cool and serve
   Allow the cake to cool in the pan for 15 minutes before serving. For the best flavor and texture, serve warm. This cake pairs perfectly with coffee or tea.