Preheat oven to 350F and use muffin pan, lined with paper liners.
In a small bowl, mix together flour, baking powder and salt.
In a large bowl, whisk together sugar, butter and egg until smooth. Add yogurt, lemon zest and juice and lemon extract, beating until smooth. Add flour mixture, beating just until smooth.
Scoop batter into prepared pan. Bake in preheated oven for 22 to 25 minutes or until tops of cupcakes spring back when lightly touched. Let cool in pan on rack for 10 minutes. Remove from pan and let cool completely on rack.