Preheat oven to 350°F (175°C). Spray a 10-inch bundt pan with nonstick cooking spray and set aside. (Ensure there is at least 1.5 inches between the height of the batter and the top edge of the pan.)

In the bowl of a stand mixer with a paddle attachment, beat the unsalted butter until smooth.

Gradually add the granulated sugar and mix until the mixture is light and fluffy.

Add the eggs, one at a time, mixing well after each addition. Add vanilla extract. Scrape down the sides of the bowl as needed.

In a separate bowl, whisk together the all-purpose flour, kosher salt, and baking soda.

On low speed, beat in the flour mixture alternately with the sour cream, beginning and ending with the flour mixture.

Add the diced peaches and gently fold them into the batter by hand with a spatula.

Pour the batter into the prepared bundt pan, filling it about ¾ of the way full. Bake for 1 hour 20 minutes to 1 hour 30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs, but no wet batter. Do not underbake.

Allow the cake to cool in the pan for 10-15 minutes before inverting it onto a wire rack to cool completely.

In a medium bowl, combine the confectioners' sugar and 1 tablespoon of milk (or cream). Whisk until smooth, adding more milk gradually until the glaze reaches your desired consistency.

Pour the glaze over the completely cooled cake and serve.