Preheat oven to 350°F (175°C). Grease and flour a standard 9x5 inch loaf pan.

In a medium bowl, whisk together the flour, baking soda, cinnamon, and salt. Set aside.

In a large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-4 minutes. Beat in the eggs one at a time, then mix in the buttermilk and vanilla extract until just combined.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just incorporated. Do not overmix. Gently fold in the diced fresh peaches using a spatula.

Pour the batter evenly into the prepared loaf pan. Bake for 50-55 minutes, or until a wooden skewer inserted into the center comes out clean. If the top browns too quickly, cover loosely with foil for the remainder of the baking time.

Let the bread cool in the pan for 10 minutes before carefully turning it out onto a wire rack to cool completely.

To make the optional glaze, whisk together the powdered sugar, milk/juice, and vanilla extract until smooth. Drizzle generously over the cooled peach bread before slicing and serving.