Preheat oven to 350°F and line two muffin tins with cupcake wrappers.
In the bowl of an electric mixer, or with a hand mixer, cream butter and sugar together until light and fluffy, about 2 minutes. Add eggs one at a time, beating until well combined before adding the next one. Add vanilla then beat to combine. With the mixer on low speed, slowly pour in half & half then beat to combine.
In a separate bowl, stir together 1 1/2 cups flour, baking powder and salt. Add the dry ingredients to the wet ingredients in three batches, mixing just until combined before adding the next batch. Toss remaining 2 tablespoons flour with the chopped peaches then gently fold into the batter.
Spoon batter into muffin tins 3/4 of the way full. Smooth tops with the back of a spoon, then bake for 15-17 minutes, or until the cupcakes are set and a toothpick inserted into the center comes out clean. Let cupcakes rest in the muffin tin for 5 minutes then remove to a wire rack to cool completely.
For the whipped cream frosting: Place the clean bowl of an electric mixer, or a large mixing bowl, into the freezer for 10 minutes. Fit the electric mixer with the whipping attachment then add whipping cream and vanilla to the chilled bowl. Beat the mixture on medium speed while gradually adding the powdered sugar. Increase the speed to high and beat until stiff peaks form. Refrigerate until ready to use.
When cupcakes are completely cool, scoop whipped cream frosting into a piping bag, then pipe onto cupcakes. Top with a fresh peach slice.