Why is my cream cheese frosting runny?
The usual culprits are over-softened cream cheese, using spreadable tub cream cheese, or mixing too long which warms it up. Use full-fat block cream cheese, keep it cool, and stop mixing once it is smooth and fluffy.
How do I thicken cream cheese frosting without adding tons of sugar?
Chill it first. Seriously. Refrigerate the bowl for 20 to 30 minutes and re-whip. If it still needs help, add 1 to 2 tablespoons more powdered sugar at a time.
If you need a little extra insurance without piling on sugar, you can add 1 teaspoon cornstarch mixed into the powdered sugar, then check the texture before adding more. Keep it conservative so it does not taste starchy. Another common option is 1 to 2 tablespoons meringue powder for structure (especially for piping), but chilling is still the cleanest first move.
Can I pipe this frosting?
Yes. For the cleanest swirls, chill the frosting for 15 to 30 minutes after mixing. If your kitchen is warm, pop the filled piping bag in the fridge for 10 minutes before piping.
Can I make it less sweet?
You can reduce the powdered sugar a bit, but less sugar also means softer structure. My favorite move is to keep the sugar where it needs to be for stability, then boost flavor with extra salt (a tiny pinch) and a squeeze of lemon for more tang.
Do I need to refrigerate cream cheese frosting?
Yes. Cream cheese frosting should be refrigerated for food safety. For serving, a frosted cake or cupcakes can usually sit out at room temperature for up to 2 hours (less if it is hot out). When in doubt, follow your local food-safety guidance.