Step 1
Combine pureed peaches and sugar for filling in a medium saucepan over medium heat. Bring to a slight boil.
Step 2
Mix cornstarch and water together in a separate bowl until there are no lumps. Stir mixture into the pan. Reduce heat to medium-low and cook until thick and bubbly about 1 minute. Let filling cool completely.
Step 3
While filling cools preheat the oven to 350 degrees F (175 degrees C). Line two 12-cup muffin tins with paper liners.
Step 4
Whisk flour baking powder baking soda and salt together in a medium bowl for cupcakes.
Step 5
Beat sugar and butter together in a large bowl using an electric mixer until creamy. Beat in eggs vanilla extract and peach extract until smooth. Add 1/2 of the flour mixture and stir until combined. Add buttermilk and 1/2 cup pureed peaches; stir until almost combined. Add remaining flour mixture and stir until all ingredients are mixed in.
Step 6
Spoon batter into the prepared muffin cups filling each 2/3 full.
Step 7
Bake in the preheated oven until tops spring back when lightly pressed 18 to 20 minutes. Cool in the tins for 10 minutes. Transfer to a wire rack and let cool about 20 minutes.
Step 8
Remove a bit of the center of each cupcake using a cupcake corer; fill with cooled peach filling.
Step 9
Beat whipping cream pudding mix and vanilla extract for frosting together using a wire whisk attachment until firm peaks form. Frost cooled cupcakes.