Preheat the oven to 375 degrees F (190 degrees C). Sift together flour, baking powder, baking soda, and salt.
In a mixing bowl, cream together butter and sugar replacements. Beat in egg and vanilla. Mix in flour mixture. Stir in pecans. Drop by rounded teaspoon onto ungreased baking sheet.
Bake in preheated oven for about 10 minutes. Cool cookies slightly before removing from pan.
