Preheat oven to 350°F.

Line 12-cup muffin pans with paper liners and spray with organic baking spray.

Sift flour and next 4 ingredients into large bowl.

Add melted butter, oil, eggs, sugar and whisk to blend. Add yogurt, milk, vanilla extract, and lemon peel stir to blend.

Pour flour mix into wet mix and whisk until completely blended.

Stir in blueberries gently.

Use 2" scoop to fill up each muffin tin.

Bake cupcakes 22-25 minutes, or until toothpick inserted into center comes out clean. Transfer cupcakes to racks to cool.

Add butter to an electric mixer and beat butter on high until creamed about 5 minutes.

Lower speed of mixer to slow and slowly add confectioners sugar.

When completely blended add maple syrup and increase mixer speed to high. Blend for 30 seconds - 1 minute until incorporated. This is a stiff frosting, but if it is too thick add a dash (1 tablespoon) cream or milk to thin.