Allow butter and eggs to stand at room temperature for 30 minutes. Meanwhile, line twenty-six 2-1/2-inch muffin cups with paper bake cups. In a medium bowl stir together flour, baking powder, and salt. In a small bowl stir together brown sugar, pecans, and cinnamon. Set aside.
Preheat oven to 350 degrees F. In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Gradually add granulated sugar, about 1/4 cup at a time, beating on medium speed until combined, scraping sides of bowl occasionally. Beat on medium speed for 2 minutes more or until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Alternately add flour mixture and milk to butter mixture, beating on low speed after each addition just until combined (batter may look curdled).
Spoon about 1 tablespoon batter into each prepared muffin cup. Sprinkle about 1 teaspoon of the brown sugar mixture over batter in cups. Spoon remaining batter evenly over brown sugar mixture in cups. Sprinkle remaining brown sugar mixture over batter in cups.
Bake for 18 to 20 minutes or until a toothpick inserted in centers comes out clean. Cool cupcakes in muffin cups on wire racks for 10 minutes. Remove cupcakes from muffin cups. Cool completely on wire racks.
Spread or pipe Creamy Butter Frosting onto cupcakes. Store cupcakes in the refrigerator. Makes 26 (2-1/2 inch) cupcakes.
For the frosting: Allow butter to stand at room temperature for 30 minutes. In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Beat in vanilla and salt. Gradually add 4 cups of the powdered sugar, beating until combined. Beat in the 1/4 cup whipping cream. Beat in the rest of the powdered sugar. Beat in additional whipping cream until frosting is light and fluffy and reaches a spreading (or piping) consistency. Makes 4 cups.
Variation: Honey Bun Cupcakes: Prepare and bake cupcakes as directed through Step 4, except cool cupcakes in muffin cups on wire racks for only 10 minutes. Meanwhile, in a medium bowl stir together 2 cups powdered sugar and 2 tablespoons honey. Add 2 to 3 tablespoons milk, 2 teaspoons at a time, to make a mixture of glazing consistency. Using a wooden toothpick, poke holes into tops of warm cupcakes. Spoon glaze over cupcakes, spreading evenly. Serve warm. Makes 26 (2-1/2 inch) cupcakes.