• Preheat the oven to 350℉/180℃. Line a 9x9 pan with parchment paper and set aside. Slice the peaches into small pieces and set aside.
  2 1/2 cups ripe peaches

For the streusel

• In a bowl, add the butter, white sugar, brown sugar, flour, and cinnamon. Mix together with your hands or a fork until combined. Then set aside in the fridge while the batter is made.
  1 cup all-purpose flour, 1/2 cup white sugar, 1 tbsp light brown sugar, 6 tbsp unsalted butter, 1/8 tsp cinnamon

For the cake

• In a bowl, add the flour, baking soda, baking powder, cornstarch, cinnamon, and salt. Stir to combine and set aside.
  2 cups all-purpose flour, 3/4 tsp baking soda, 3/4 tsp baking powder, 1/4 tsp salt, 1 tbsp cornstarch, 1/4 tsp cinnamon
• In a large bowl, add the white sugar and eggs. Whisk vigarously for 2-3 minutes until well combined.
  3/4 cups white sugar*, 2 large eggs
• Add in the oil and continue whisking until smooth.
  2/3 cups oil
• Add in the sour cream and vanilla. Continue to whisk together.
  1 tbsp vanilla, 2/3 cups sour cream
• Add the dry ingredients in. With a spatula, gently stir just until a soft cake batter forms. Do not over-mix!
• Transfer into the prepared pan and spread evenly. Add the sliced peaches on top, and the sprinkle the streusel.
• Bake for 50-65 minutes or until a toothpick inserted in the middle comes out clean. If it is still wet with batter, it is not ready. When baked, allow to cool before slicing. Enjoy!