Chop fresh, peeled peaches and combine in a saucepan with granulated sugar, cinnamon powder, and lemon juice over medium heat. Stir for 5-7 minutes until thickened. Transfer to a bowl, cover, and refrigerate for at least 2 hours.

Preheat the oven to 350°F (175°C) and line muffin tin with cupcake liners. Mix flour, baking powder, baking soda, and salt in a bowl. In another bowl, beat butter with sugars until fluffy. Add eggs and vanilla. Gradually incorporate dry mixture and milk for a smooth batter.

Divide the batter among muffin cups, filling each about two-thirds full. Bake for 18 minutes or until tops spring back when lightly pressed. Cool for 5 minutes, then transfer to a wire rack.

Beat butter in a large bowl until fluffy, then gradually add powdered sugar. Mix in heavy cream and cinnamon, beating until reaching creamy consistency.

Hollow out centers of cooled cupcakes, fill with peach filling, and frost the tops with spiced buttercream. Sprinkle with streusel crumbs as a topping.