Preheat the oven to 350 degrees F. Spray a mini muffin tin with cooking spray.
With a hand mixer, cream together sugar and butter. Add egg and vanilla.
In separate bowl, combine sour cream, salt and soda. Add flour and sour cream to butter mixture, beat until smooth.
Scoop dough out using a 2 TBSP cookie scoop and put one in each mini muffin cup. No need to roll the dough to make it smooth - it will all bake the same.
Bake cookies for 15-18 minutes, making sure they're not getting too brown at the end. {If they are, pull them out.}
Right after you take them out, use a small measuring spoon to push into the middle of each cookie cup, creating a space for the cherries to go. Don't push through cookie completely.
Let cool in the pan for 10-15 minutes, then gently run a thin knife along the sides to pop them out.
Open the can of cherry pie filling and transfer to a bowl. Use a fork to fill each cookie cup with cherries.
Drizzle tops with melted white chocolate, if desired. Enjoy!