Using a stand or hand mixer, beat the butter until it is soft and fluffy about 5-7 minutes. Using room temperature butter will help speed up this process.
Incorporate powdered sugar ½ cup at a time, waiting until fully combined before adding more.
Once all the powdered sugar is mixed in, add the salt and vanilla extract. At this point, scrape down the sides of the bowl to make sure everything is fully combined.
Pour the whipping cream in a slow, steady stream while beating the buttercream.
If you prefer your buttercream to be plain vanilla flavor, you can skip this step. To get the full orange espresso flavor, add the espresso powder, orange zest and orange emulsions, mixing until fully combined.
If you don't have a piping bag, you can cut one corner off a Ziploc bag and use it to pipe, or simply spread the frosting onto the cupcakes with a butter knife.
Once the cupcakes have cooled fully, frost your cupcakes however you'd like. Incorporate some food dye into the buttercream for an extra burst of color!