Credit goes to Martha Stewart's Apple and Sour Cream Coffee Cake recipe, all I did was replace apples with pears. In hindsight, it's very sweet so when I make this again I plan to reduce the sugar by 1/2 cup in the cake mix.
TIP: I've found pears can make this type of cake very moist so it's best to eat within two days of baking. Fortunately it freezes very well. You can either pull it out of the freezer the night before or microwave for 30 seconds to thaw the center and then bake in the oven for 5 or 7 minutes on 350.