Heat oven to 350°F. Line three mini cupcake pans with 12 foil or paper liners each (total of 36).
In a medium-size bowl, whisk flour, baking powder and salt. Set aside.
In a large bowl, with mixer, beat butter and sugar. Add eggs, one at a time. Beat until light and smooth, 3 minutes. Add half the flour mixture, followed by milk, then remaining flour mixture. Stir in butter flavoring and chopped pecans.
Spoon batter into prepared cups. Bake at 350°F for 18 to 22 minutes, or until browned. Remove from pan; cool on rack.
On low speed, beat confectioners sugar, butter, milk, and flavoring until smooth in texture (adding more milk if necessary). Spread onto cupcakes; garnish with pecans. To make standard-size cupcakes: Line two standard cupcake pans with 20 foil or paper liners. Spoon batter into cups; bake at 350°F for 24-26 minutes. Frost as directed.