1️⃣ Prepare the custard base
In a saucepan over medium heat, combine the heavy cream, milk, sugar, and hibiscus powder. Stir occasionally until the sugar dissolves and the mixture is warm but not boiling. In a separate bowl, whisk the egg yolks until smooth. Slowly pour ¼ cup of the warm cream into the yolks while whisking constantly. Repeat with another ¼ cup, then gradually pour the tempered yolks back into the saucepan, stirring continuously.

2️⃣ Infuse with rose flavor
Cook the custard over low heat, stirring frequently, until it thickens enough to coat the back of a spoon. Remove from heat and stir in the rosewater (and optional vanilla or cardamom). Ensure the hibiscus powder has fully dissolved; strain through a fine-mesh sieve for a smooth texture.

3️⃣ Chill the mixture
Transfer the strained custard to a clean bowl. Cover with plastic wrap, pressing it directly against the surface to prevent a skin from forming. Refrigerate for at least 4 hours or overnight.

4️⃣ Churn the ice cream
Pour the chilled custard into an ice cream maker and churn for 20–25 minutes until it reaches soft-serve consistency. No ice cream maker? Pour into a shallow dish and freeze, stirring every 30 minutes for 3–4 hours to break up ice crystals.

5️⃣ Freeze until firm
Transfer to an airtight container and freeze for at least 2 hours. Let it sit for 5 minutes before scooping. Garnish with dried rose petals, pistachios, or white chocolate shavings.