1. Prepare the Oven and Pan:

• Preheat the oven to 350°F (175°C).

• Grease and flour a 9-inch round cake pan or an 8×8-inch square baking pan.

2. Make the Cake Batter:

• In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt. Set aside.

• In a large bowl, beat together the softened butter and granulated sugar until light and fluffy, about 2-3 minutes.

• Add the eggs one at a time, beating well after each addition.

• Stir in the pumpkin puree and vanilla extract until fully incorporated.

• Alternate adding the dry ingredients and sour cream (or Greek yogurt) to the wet ingredients, starting and ending with the dry ingredients. Mix until just combined—be careful not to overmix.

3. Prepare the Cinnamon Swirl:

• In a small bowl, combine the brown sugar and cinnamon. Set aside.

4. Prepare the Streusel Topping:

• In another small bowl, combine the flour, oats, brown sugar, cinnamon, and a pinch of salt.

• Stir in the melted butter until the mixture becomes crumbly.

5. Assemble the Coffee Cake:

• Pour half of the cake batter into the prepared pan and spread it into an even layer.

• Sprinkle the cinnamon-sugar swirl evenly over the batter.

• Top with the remaining batter and spread it into an even layer, covering the cinnamon-sugar mixture.

• Sprinkle the streusel topping evenly over the top of the cake.

6. Bake the Cake:

• Bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean (a few crumbs are okay).

• If the top begins to brown too quickly, cover the cake loosely with foil during the last 10 minutes of baking.

7. Cool and Serve:

• Let the cake cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.

• Slice and serve. This cake is perfect with a warm cup of coffee or tea!