Make the cupcakes: Preheat oven to 350°. Line two 12 capacity cupcake tins with paper liners (if you only have one tin, bake in 2 separate batches).
Beat butter, marmalade and sugar at medium speed with an electric mixer in a large bowl; beat in eggs one at a time.
Combine cream and next 3 ingredients in a medium bowl. Combine flour, baking powder, soda and salt in a large bowl; add to butter mixture, alternating with cream, beginning and ending with flour. Spoon batter into prepared muffin pans, filling cups 2/3 full.
Bake 15-20 minutes or until a toothpick inserted in center to wire racks; cool completely.
Make the filling: Combine the cornstarch and cold water in a small condiment cup. Mix well until blended and no lumps remain.
Place the peaches in a medium saucepan over medium-high heat. Add the cornstarch mixture. Cook until the mixture bubbles and thickens slightly. Remove from the heat. Stir in the peach liqueur or flavoring oil. Transfer the mixture to a shallow dish and refrigerate until completely cool, about 30 minutes to 1 hour. When the mixture is cool fill the cupcakes. Use a small serrated knife to cut out a divot in the tops of the cupcakes (discard the cake cut-outs or save them for a snack). Fill the cupcakes with the peach filling.
Make the frosting: Place the butter in the bowl of an electric mixer. Beat until creamy on high speed. Add the confectioners’ sugar and beat on low speed until just combined (mixture may be crumbly). Add the orange zest, peach schnapps (or flavoring oil) and vanilla extract. Beat on high speed until fluffy. If the mixture is stiff or crumbly, add milk or cream 1 tablespoon at a time with the mixer running, until the frosting is whip-able and of piping consistency. Beat until the frosting is light (almost white) in color, about 5 minutes more.
Garnish the cupcakes with orange zest or candy. I used Satellite Wafers candies which can be found in bulk candy stores and online (see blog post for links).