Peel and chop 2-3 peaches. In a saucepan over medium heat, combine peaches with 1/4 cup granulated sugar, 1/2 teaspoon cinnamon, and 1 tablespoon lemon juice. Cook for about 8-10 minutes until thick and syrupy.

Mix 1 tablespoon of cornstarch with 2 tablespoons of water, add to the saucepan, and cook for an additional 2-3 minutes until thickened. Remove from heat and cool completely.

Preheat your oven to 350°F (175°C) and line a cupcake pan with cupcake liners.

In a mixing bowl, sift together 1 1/2 cups of all-purpose flour, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/4 teaspoon fine sea salt.

Cream together 1/2 cup unsalted butter, 1/2 cup granulated sugar, and 1/4 cup brown sugar until light and fluffy, about 3-4 minutes. Gradually add in 1/4 cup vegetable oil, then beat in 2 eggs, one at a time, along with 1 teaspoon vanilla extract.

With the mixer on low, gradually add the dry mixture to the butter mixture, alternating with 1/2 cup of milk, until just combined.

Spoon the batter into prepared cupcake liners, filling each about two-thirds full, and bake for approximately 18-20 minutes until springy and a toothpick comes out clean.

While the cupcakes are baking, beat 1/2 cup unsalted butter until fluffy, about 3-4 minutes. Gradually add 3 cups powdered sugar, 1 teaspoon cinnamon, and 1/4 teaspoon nutmeg, mixing on low.

Add 2 tablespoons of heavy cream and beat on high until creamy and smooth, adjusting the cream as needed.

Once cooled, use a cupcake corer to remove the centers. Fill each with peach filling and frost with spiced buttercream, finishing with streusel crumbs on top.