Cinnamon-Sour Cream Streusel Loaf

½ cup butter, softened
1 cup sugar
1 egg
1 ¼ cups flour
½ tsp baking powder
½ tsp salt
½ cup sour cream
½ tsp vanilla
½ cup chopped pecans
¼ cup firmly packed brown sugar
1 T sugar
½ tsp cinnamon

Beat butter at high speed with an electric mixer until creamy; gradually add 1 cup sugar, beating well.  Add egg, beating until blended.
Combine flour, baking powder, and salt; add to butter mixture alternately with sour cream, beginning and ending with flour mixture.  Beat at low speed just until blended.  Stir in vanilla.
Combine pecans and next 3 ingredients.  Pour half of batter into a greased and floured 8 ½ x 4 ½ inch loaf pan; sprinkle with half of pecan mixture.  Pour remaining batter into pan; top with remaining pecan mixture.
Bake at 350 for 1 hour or until a wooden pick inserted in center comes out clean.  (Cover with aluminum foil for the last 20 minutes of baking to prevent excessive browning, if necessary.)  Cool in pan on a wire rack 10 minutes; remove from pan, and cool completely.
Note:  This recipe may be doubled to make 2 loaves.