Preheat oven to 350 degrees F. Grease springform pan and set aside.
In a large bowl, combine butter, milk, brown sugar, sour cream, vanilla, and egg Stir in baking powder, and cinnamon.
Add flour a little at a time until just combined. Do not over-mix.
Fold in peaches. Pour into prepared pan.
For the crumb toppings
Combine all ingredients in a medium bowl. Cut in butter using 2 forks until crumbly.
Sprinkle over batter, and bake for 55-60 minutes.
For the Glaze
In a small bowl, combine all ingredients. Drizzle over cake and enjoy.
Notes
Ingredient Notes and Shopping Tips
Fresh Peaches: I used fresh ripe peaches from my local farmer's market in this recipe. Gently press near the stem end. You want peach with a slight give and a sweet aroma Rock-hard fruit needs a day or two to ripe while overly soft fruit is likely mushy and too ripe. Can also use frozen or canned.
Milk and Sour Cream: For the best results use full-fat sour cream and whole milk. You can use Greek yogurt instead of sour cream if that's what you have on hand.
Butter: Use softened, unsalted butter for both the cake batter and the crumb topping. It should be soft enough that your finger makes an indent when you touch it.
Flour: Measure your flour correctly by fluffing it with a fork, spooning into a measuring cup, and then leveling off with a fork.
Krystle's Tips
Use Room Temperature Ingredients: This helps the ingredients come together smoothly and bake evenly.
It's Okay If the Batter Is Thick: The batter will be thicker than your typical cake batter.
Don't Overmix: Stir only until no white streaks remain.
Don't Overbake: Ovens vary start testing about 5 minutes before you think it should be done. A toothpick inserted near the center should come out with just a few moist crumbs. If you see raw batter keep baking a few minutes at a time.