Cut three medium-size peaches in reasonably small pieces. You want about 2-½ cups. Juice 1 lemon, you need ½ TBSP.
Add the sugar, lemon juice, corn starch, and water to a saucepan and bring to a boil over medium-high heat. Lower the heat to a low boil while you stir or whisk to eliminate any lumps. You want the syrup to thicken, which takes about 5- 8 minutes. Once it has thickened, take the pan off the heat and add the vanilla extract, cinnamon, and peaches to the saucepan. I poured the peach filling into a bowl and let it cool completely. Then, I add it to a glass container and put it in the refrigerator. I like to keep it in the fridge overnight.
Weigh or measure into one bowl the flour, baking powder, and salt, running a whisk through to blend. In a stand or hand-held mixer on medium speed cream the butter and sugar for 2 -4 minutes or till light in color and fluffy. Add the vanilla extract and egg blend till incorporated. Turn the mixer to low and gradually add the flour mixture. You want to mix till the flour is incorporated.
Using a mini muffin pan (mine makes four dozen at one time) spray with Pam even if it is a non-stick pan. I am using a small cookie scoop and roll the cookie dough in your hand until you have a ball and drop it into one of the mini molds in the pan. I save a little of the cookie dough in the bowl just in case I need to add a small amount to add to one of the balls that might be a little small in size.
A great way to create the cups is by using a tart tamper. I used the smaller end to press down the cookie ball until it made the shape of a cup. After you have created all the cookie cups, fill each one with the peach pie filling. I did about four peach pieces per cookie cup. The juice I only added until it filled the cup about ¾ of the way.
Preheat the oven to 350° and bake for 12-14 minutes. These will be longer than the average sugar cookie, the sides need to become firm to hold the peaches. If you touch the cookie part of the cup and it is firm pull it out of the oven. !!! IMPORTANT let them set in the pan till entirely cooled - at least 20 minutes. You want the pan cool to the touch before you try and get the cups out of the mold. I take a butter knife and go straight down the side of the cookie cup, and it should lift easily. If you try lifting the cookie cup before it has cooled, it will start to fold into itself and will get messy fast, once out of the pan, move to a cooling rack. I add just a little Cool Whip on the tops of mine, but that is optional.