Preheat oven to 325°F. Grease and flour a 12-cup Bundt pan.
Toss diced peaches with 1 tablespoon flour to prevent sinking.
Cream butter and sugar until light and fluffy. Add eggs one at a time.
Mix in vanilla and almond extract. Alternate adding flour mixture and sour cream.
Fold in peaches gently. For streusel, mix brown sugar, cinnamon, and flour, then cut in cold butter.
Pour half batter into pan, sprinkle streusel, add remaining batter. Bake 65–75 minutes.
Cool 15 minutes, invert onto rack. Whisk powdered sugar, milk, and vanilla for glaze. Drizzle over cooled cake.