Preheat the oven to 350 degrees F.
Grease and flour a 10 cup bundt pan (see Notes below)
In a separate bowl add the flour, baking soda, cinnamon and salt. Whisk to blend, set aside.
Add the vanilla extract to 1 cup of sour cream, set aside.
Mix the butter on medium speed until smooth and creamy. Add the white and brown sugar gradually and mix on medium speed 3 to 5 minutes, or until the mixture is light and fluffy.
Add the eggs one at a time, mixing after each until the yolk is blended.
With the mixer on low speed, add the flour mixture alternately with the sour cream mixture. Begin and end with dry ingredients. Add the dry ingredients 3 times and the sour cream mixture twice. Mix just until incorporated.
Gently fold the diced peaches and crushed pecans into the cake batter. Scoop the batter into a bundt pan.
Bake at 350 degrees for 1 hour (adjust time as needed). When a toothpick inserted into the center comes out clean or with just a few crumbs attached, it is done. Baking times can vary depending on the size and type of pan you are using. Peek in as the end time approaches and adjust as needed.
Allow to cool 10 minutes before turning out. Do not allow to cool too long or it may stick to pan.