
Preheat the oven to 180°C (356°F). In a bowl, mix together the butter, powdered sugar, fine sugar, and salt. Then whisk until well combined and fluffy.
Gradually add the whipping cream in 3 portions, beating on low speed after each addition.
Add the cake flour to the butter mixture and mix well. Then, pour the mixture into a piping bag fitted with a star piping tip.
Pipe the batter onto a lined baking sheet.
Bake for 10-12 minutes or until the edges turn slightly brown. Do not overbake. Let cool and store in an airtight container for up to 5 days.