Step 1

Preheat oven to 350 degrees. Spray a 9-inch springform pan with non-stick cooking spray.

Step 2

To make crumbs:

Step 3

In a mixing bowl whisk together flour, brown sugar, granulated sugar, cinnamon, ginger, nutmeg and salt until well blended (break any clumps of brown sugar up with fingertips). Pour in melted butter and using a rubber spatula, fold mixture until evenly moistened. Set aside.

Step 4

To prepare cake:

Step 5

In a separate mixing bowl whisk together flour, baking powder, baking soda and salt for 20 seconds, set aside (peel and slice peaches now if you haven't already). In the bowl of an electric stand mixer fitted with the paddle attachment, whip together butter and granulated sugar until pale and fluffy.

Step 6

Mix in eggs one at a time adding in vanilla with second egg.

Step 7

Add 1/3 of the flour mixture to the butter/egg mixture and mix just until combined, then pour in buttermilk and mix just until combined. Mix in another 1/3 of the flour mixture and mix just until combined, then mix in sour cream. Finish by mixing in last 1/3 of the flour mixture and mix until nearly combined, then remove bowl and scrape bowl and fold batter just to combined.

Step 8

Pour batter into prepared pan. Top evenly with peaches then evenly sprinkle crumb mixture into very small crumbles over peaches.

Step 9

Bake in preheated oven until center of cake is set (it shouldn't jiggle or sink when touched, and toothpick should come out free of batter), about 50 - 55 minutes. Cool on a wire rack (you don't need to cool entirely, this cake is really good warm), then drizzle with glaze if desired.

Step 10

For the glaze:

Step 11

Whisk together powdered sugar, half and half and vanilla in a bowl until well blended. Add more half and half to thin as desired or more powdered sugar to thicken if needed.