Preheat oven to 325°F. Grease and flour a 10-inch Bundt pan.
Peel and dice peaches; toss with lemon juice and set aside.
Whisk together flour, baking powder, baking soda, and salt.
Beat butter and sugar for 4-5 minutes until light and fluffy.
Add eggs one at a time, then vanilla extract.
Alternate adding dry ingredients and buttermilk, beginning and ending with flour mixture.
Gently fold in diced peaches.
Pour batter into prepared pan and smooth top.
Bake 60-70 minutes until a wooden skewer comes out clean.
Cool in pan for 15 minutes, then invert onto cooling rack.
Mix powdered sugar, peach puree, and buttermilk for glaze.
Drizzle glaze over completely cooled cake.