In a large mixing bowl or the bowl of a stand mixer fitted with a whisk attachment, add room temperature unsalted butter. Whip the butter for 5 minutes on medium-high speed, scraping down the sides occasionally. The butter will be light, fluffy, and pale in color.
Add one half of the powdered sugar and mix on the lowest speed setting until fully combined. Add remaining powdered sugar and continue to mix on low until incorporated.
Add almond extract and salt and mix on low until combined.
Drizzle in heavy cream and maraschino cherry juice while continuing to mix on low speed.
Once the heavy cream and cherry juice are added, turn the speed on the mixer to medium-high and whip for an additional 3 minutes. Scrape the sides of the bowl occasionally to ensure the frosting is well mixed.
If desired, switch to a paddle attachment on the stand mixer and mix buttercream on low speed for 2 additional minutes to remove air bubbles to create smooth frosting.
Use a piping bag and a Wilton 1M piping tip to swirl the cherry almond buttercream frosting onto the cherry almond cupcakes in a ruffle swirl.