Preheat oven to 350°F
Grease and flour 9-in baking pan
In a large bowl or mixer cream together butter and sugar until light and fluffy (3-4 minutes)
Beat in eggs one a time, combining well between additions
Add sour cream and vanilla extract until well combined
In a separate bowl whisk flour, baking powder, baking soda, and salt together
Add dry ingredients to wet ingredients slowly, stirring until combined but not overmixed
Make the topping by combining brown sugar, pecans, cinnamon, and nutmeg until crumbly in texture
Assemble the coffee cake by pouring half of the batter into the pan, top with half the topping mix and repeat with the remaining ingredients
Bake 40-45 minutes or until a cake pick comes out clean when inserted into the cake
Let cool for at least 15 minutes before serving. Enjoy!