Preheat the oven to 350°F (175°C). Line a cupcake pan with cupcake liners.
In a mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and peach puree.
In a separate bowl, combine the flour, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, alternating with the sparkling wine. Mix until just combined.
Distribute the batter evenly among the cupcake liners, filling each about two-thirds full.
Bake in the preheated oven for about 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
While the cupcakes are cooling, prepare the frosting. In a mixing bowl, beat the softened butter until creamy. Gradually add the powdered sugar, mixing until smooth.
Add the peach puree, sparkling wine, and vanilla extract to the frosting and mix until well combined.
Once the cupcakes are completely cool, frost them with the peach frosting using a knife or piping bag. Garnish with fresh peach slices if desired.