Preheat oven to 350ºF. Prepare the muffin pan with paper liners.
Whisk flour, baking powder, and salt in a bowl. Set aside.
In another bow, mix sugar, butter, and egg until smooth. Add yogurt, lemon zest, and lemon juice, and beat well. Stir in the flour mixture and mix just until combined.
Spoon the batter into the prepared pan, about 2/3 full. The recipe will make about 10-12 cupcakes.
Bake in the oven for 22-25 minutes or until toothpick comes out clean. Cool in pan for 10 minutes, remove from the pan and cool completely.
For the glaze, mix all the glaze ingredients well until smooth. Spoon over the cupcakes, and decorate with marshmallow peeps as you like.