Toss the apples and sugar together in a medium bowl.

Heat a medium skillet over medium high heat and melt the butter. Whisk in the cinnamon.

Add in the apples and the water. Cook for 5-7 minutes or until softened.

In a small bowl, whisk the cornstarch and water until combined. Pour into the apple mixture and stir in. Cook for another 2 minutes, stirring frequently, until the mixture thickens.

Remove from the heat and set aside.

Preheat the oven to 350 degrees. Line two cupcake pans with liners.

Combine flour, baking soda and salt together in a medium bowl.

Add the butter to a stand mixer and beat on medium speed until light and creamy, about 3 minutes. Add in the egg whites slowly until fully combined. Mix on medium speed for another 2 minutes.

Alternate between the flour mixture and the milk until combined. Add in the vanilla bean paste and mix for another minute.

Fill each cupcake cavity ½-2/3 of the way full.

Bake for 20-22 minutes or until lightly golden and a toothpick inserted in the center comes out clean.

Transfer cupcakes to a wire rack to cool completely.

Add the butter to a stand mixer and beat on medium speed for 5 minutes.

Add in the powdered sugar 1 cup at a time. Add in the cinnamon, milk and salt and mix until combined.

Use a paring knife to cut a small circle out of the top of each cupcake.

Fill each cupcake with 1 heaping teaspoon of the apple pie filling.

Transfer the buttercream frosting to a piping bag and pipe on the frosting.

Cupcakes will keep for 3 days at room temperature.