Spray an 8-x-8-inch baking dish with nonstick spray. Preheat oven to 350 degrees F.
1. In a small bowl, combine 3 teaspoons sugar and corn starch. Toss peaches in the mixture and coat evenly. Set aside.
2. In a medium bowl, sift together 1 cup sugar, flour, salt and baking powder. In another bowl, whisk together milk and butter. Slowly pour wet ingredients into dry ingredients and stir until incorporated.
3. Pour cake batter into prepared baking dish. Press sliced peaches into the cake batter and place some on top. Put in the oven and bake for 60 minutes or until a toothpick inserted in the middle comes out clean.
Peach Cobbler Snack Cake will keep up to 3 days stored in an airtight container.