Apple Cinnamon Cupcakes

For the cupcakes
1/2 cup (1 stick or 115g) unsalted butter, melted and slightly cooled
2/3 cup (135g) packed light or dark brown sugar 
1/3 cup (65g) granulated sugar
2 large eggs, at room temperature
1/2 cup buttermilk
2 teaspoons pure vanilla extract
1 1/2 cups (190g) all-purpose flour
1/2 cup quick oats (50g)
1/4 teaspoon baking soda
1 teaspoon baking powder
1/2 teaspoon salt
1 teaspoon ground cinnamon (can substitute cardamom.)
1/4 teaspoon ground nutmeg
2 cups finely chopped baking apple (peeled) such as a Granny Smith (about two apples).

Maple Buttercream
1 cup (2 sticks pr 230g) unsalted butter at room temperature
4 cups powdered (icing) sugar
1/2 teaspoon of salt
4 tablespoons maple syrup
1 tsp vanilla extract
12-15 maple leaf cookies (you can buy these at most grocery stores or make your own)

Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with cupcake liners. Line a second pan with 3 liners – this recipe makes about 15 cupcakes. Set aside.

Make the cupcakes: Whisk the melted butter, brown sugar, and granulated sugar together in a medium bowl until combined. Whisk in the eggs, one at a time, until smooth then whisk in the vanilla extract and milk. Set aside.

Whisk the flour, baking soda, baking powder, salt, cinnamon, and nutmeg together in a large bowl.  Slowly add the wet ingredients to the dry ingredients and stir gently until combined. The batter will have a few lumps and seem thin but will thicken. Fold in the apples.

Fill the cupcake liners 3/4 of the way full with batter. Bake for 21–23 minutes, rotating the pan halfway through baking. A toothpick inserted in the center of a cupcake in the middle will come out clean when done. Remove from the oven and allow to cool in the pan for about 10 minutes, then remove to a rack to cool completely before frosting.

Make buttercream: While the cupcakes are cooling place the butter in a large bowl and using an electric hand mixer if you have one (if not a wooden spoon will work too but you’ll get an amazing arm workout) whip the butter until it is light and airy.

Add in the powdered sugar one cup at a time mixing in each cup until it is incorporated before adding the next one. Once all the sugar is added, add the salt, vanilla and maple syrup and continue to beat or stir until it is really light and fluffy.

Using a pastry bag, or a large zipper storage bag spoon all of the frosting in to the bag, and cut the tip off the pastry bag so you will have an opening about the size of a quarter (cut one of the lower corners of the zipper bag the same way.) Squeeze a large dollop of icing on to each cupcake, just so it almost comes to the edge of the cupcake wrapper. Using one of the cookies, push down on the dollop so that the cookie rests flat as a topper.