Peel and dice peaches into 1/2 inch pieces; toss with lemon juice, cornstarch, and cinnamon, then set aside.

Whisk together flour, baking powder, baking soda, and salt in a separate bowl.

Cream butter, granulated sugar, and brown sugar until light and fluffy (3–4 minutes).
Add egg and vanilla extract to the butter mixture; mix until fully combined.

Gradually stir dry ingredients into the wet mixture until just combined; chill dough for 30 minutes.

Roll half the dough to 1/8 inch thickness; cut out 3-inch round bases and place on parchment-lined sheet.

Spoon peach filling onto each base; use remaining dough to cut thin strips and form lattice tops.

Bake at 350°F (175°C) for 13–16 minutes until edges are golden and filling is bubbling.

Cool on baking sheet for a few minutes, then transfer to wire rack to cool completely.