Preheat the oven to 350°F. Lightly spray a 9×13 inch baking pan and set aside.
In a large bowl, beat together the 1/2 cup butter and 1 1/2 cups sugar until light and fluffy. Add in the eggs, sour cream and vanilla, and beat until fully combined.
In a separate bowl, mix together the 2 cups flour, 1 1/2 teaspoons cinnamon, baking soda and salt. Slowly mix into the wet ingredients until fully incorporated. Fold in the peaches.
Pour the mixture into the prepared baking pan.
In a small bowl, mix together all of the topping ingredients. Sprinkle on top of the cake batter.
Place the cake in the preheated oven, and bake for 30-40 minutes, or until a toothpick inserted in the centre comes out clean.