2 sticks (1 cup) unsalted butter, room temperature
3 cups powdered sugar
1/4 tsp salt
1 tsp almond extract
1-2 TBS of milk to thin
Mix the water, corn syrup, white sugar, and cream of tartar in a saucepan with high sides. Bring to a boil, insert a candy thermometer and continue boiling rapidly until mixture thickens and reaches 300 degrees, stirring occasionally.
Working quickly, pour the mixture into a 9x13 cake pan or rimmed baking sheet. Allow to cool and harden completely, and then lightly smack with the smooth side of a meat tenderizer to break into shards.
Pre-heat oven to 350F. Line a 12-cup muffin tin with baking papers.
In a bowl, mix together flour, sugar, baking powder, and salt. Add the remaining ingredients and combine using a hand mixer, stopping just when the batter becomes smooth. Fill baking papers 2/3 of the way full with batter. Bake on the center rack for about 14 minutes or until a toothpick inserted in the middle comes out with only a few loose crumbs, and the tops spring back when lightly touched.
Remove from oven, allow to cool for about 5 minutes in the pan and then carefully remove the cupcakes from the pan and allow to cool completely.
Once cooled, use a cupcake core tool or small spoon and dig out a cavity in the center of each cupcake. Fill each cavity with cherry pie filling and then replace the tops with the remaining cupcake pieces.
Using a hand or stand mixer, blend together the softened butter and almond extract until smooth. Add the salt and then the powdered sugar 1 cup at a time until totally combined. Add the milk a little at a time, mixing well after each addition until the frosting has thinned enough to be easily spreadable or able to be piped.
Using a knife or a pastry bag fitted with a large round tip, apply buttercream to each cupcake. Top each cupcake with several pieces of sugar glass, and then drizzle leftover pie filling on top.