In a small saucepan on medium heat, combine peaches, brown sugar, butter and salt and cornstarch.

Stir until the butter and brown sugar have melted and the mixture starts to boil, about 3 minutes.

Continue to boil while stirring constantly for another 2 minutes.

Remove from the heat and allow the filling to cool completely.

Preheat oven to 350 degrees and line a cupcake pan with paper liners.

In a medium bowl, combine flour, baking powder, cinnamon and salt. Set aside.

In a stand mixer or in a large bowl and a hand mixer, cream together butter and brown sugar for about 4 minutes, until light and fluffy on medium/medium high speed.

Add the egg, mixing well and scraping the sides of the bowl.

In a small bowl or pourable measuring cup, whisk together milk and vanilla. Set aside.

Starting with the dry ingredients, add about ⅓ to the butter mixture and beat until combined.

Add half of the milk and mix well. Continue alternating dry and wet ingredients, ending with the dry ingredients.

Pour batter into each cupcake liner filling about ⅔ full. Bake for about 16 minutes or until a toothpick inserted in the middle of the cupcake comes out clean.

Let cool in the pan for about 10 minutes and then transfer to a wire rack to cool completely.

Using a stand mixer or mixing bowl and hand mixer, combine room temperature butter with powdered sugar.

Mix at low speed for about 2 minutes until combined. Add the milk and vanilla.

Mix at medium speed for 2 minutes until light and fluffy.

Using a knife or cupcake corer, cut a hole in the center of each cupcake making sure not to go down all the way to the bottom of the cake.

Spoon the peach filling into each cupcake, level with the top.

Frost the cupcakes with frosting using either a knife or a piping bag and piping it on each cupcake.

Decorate with fresh peach slices if desired.