Prepare your cookie dough first. Combine the salted butter, brown sugar, and granulated sugar in a large mixing bowl. Using an electric hand mixer on medium high speed, cream the ingredients together until smooth.

Add the egg and vanilla. Whisk again until the egg is fully incorporated. Gently whisk in the flour, baking powder, and baking soda. Make sure no pockets of dry ingredients remain in the cookie dough.

Drop balls of cookie dough onto a large baking sheet. Bake for 12 minutes. As soon as your cookies come out of the oven, use a small dish or the back of a spoon to create a small indent in the center of each cookie. Let your cookies cool while you prepare the filling.

Dice the peaches and then add them to a pot with brown sugar. Cook over medium heat for 5-7 minutes, or until the mixture starts to bubble.

In a small bowl, whisk together the softened butter, flour, and brown sugar. Top each cookie with a spoonful of filling followed by a sprinkle of the streusel mixture. Bake your cookies for another 5 minutes. Enjoy!