Preheat oven to 350°F. Grease a 9 x 9-inch baking dish and set aside.
Make the crumb topping: In a bowl, combine the flour, sugar, baking powder, and salt. Whisk to combine. Add the almond extract and melted butter, and stir until it forms crumbly, irregular pieces. Set aside.
1 ¼ cups all-purpose flour, ¾ cup granulated sugar, ½ teaspoon baking powder, ½ teaspoon kosher salt, ¼ teaspoon almond extract, 6 tablespoons unsalted butter
Mix the wet ingredients: In a large bowl, cream the butter and granulated sugar until light and fluffy, 3-5 minutes. Add the eggs and vanilla extract and mix well to incorporate. Then add the sour cream and mix.
12 tablespoons (1 ½ sticks) unsalted butter, ¾ cup granulated sugar, 2 large eggs, 1 teaspoon vanilla extract, 1 cup sour cream
Add the dry ingredients: Add the flour, baking powder, salt, and cinnamon, and mix until incorporated. A few dry streaks are fine. Fold in the peaches.
Assemble: Pour the batter into the prepared pan. Sprinkle the crumb mixture on top.
Bake in the preheated 350°F oven until a toothpick inserted in the middle comes out clean, 50-60 minutes. Remove from the oven and cool in the pan for 1 hour before slicing and serving.