Melt 1 teaspoon butter in bottom of a 9-inch round cake pan. Combine oats, 3 tablespoons brown sugar, and pecans. Sprinkle oat mixture over bottom of pan, and set aside.
Beat 3 tablespoons butter, granulated sugar, and 1/4 cup brown sugar at medium speed of a mixer until mixture is well-blended (about 4 minutes). Add the egg, and beat well. Lightly spoon the flour into dry measuring cups, and level with a knife. Combine flour, baking powder, pumpkin-pie spice, and baking soda. Add the flour mixture to the butter mixture alternately with the pumpkin and buttermilk, beginning and ending with the flour mixture.
Spoon batter evenly over oat mixture. Bake at 350° for 40 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 5 minutes, and invert cake onto a serving plate. Serve warm or at room temperature.
This coffee cake is very moist and flavorful. I used 1/4 cup pecans and would actually bump it up to 1/2 cup next time. I also used 1 cup all purpose flour and 1/4 cup whole wheat flour. Otherwise, I followed the recipe. The good thing about this recipe is that I found it easy to make and I had all of the ingredients on hand. It's a solid everyday coffee cake, but nothing special. Also, not all of the cake came out of the pan when I inverted it, so I had to "patch" a portion of the edge on one side. I would definitely make it again.
We love this coffee cake recipe. It is so moist and flavorful...not dry like many other coffee cake recipes. We have made this for Christmas gifts for friends and we have taken it to holiday brunches. Everyone raves about it and wants the recipe.
My son volunteered me to bring a coffee cake to school for Teacher Appreciation Day and I decided to make this one since I had all the ingredients on hand. It got excellent reviews from everyone, was very moist and just the right sweetness.