In a medium saucepan over medium heat, combine 2 cups of heavy cream, 1 cup of coconut milk, and 3/4 cup of granular sugar substitute. Stir gently for about 5 minutes until bubbles start forming along the edges, then remove from heat and let cool slightly.

In a separate bowl, whisk together 4 egg yolks until smooth. Gradually add the warm cream mixture into the egg yolks, whisking continuously. Strain through a fine mesh sieve to ensure a smooth mixture.

Return the mixture to the saucepan, add 1 cup of sugar-free white chocolate baking chips, and heat over low-medium until melted and smooth, about 3-4 minutes.

Cover the mixture with plastic wrap and refrigerate for at least 4 hours or until completely chilled.

Pour the cold mixture into your ice cream maker and churn according to the manufacturer's instructions, about 20-25 minutes.

In a small saucepan, simmer 1 cup of frozen raspberries with 2 tablespoons of sweetener for 5-7 minutes until thickened. Let cool completely.

Transfer the churned ice cream to a freezer-safe container. Drizzle in the cooled raspberry sauce, gently swirling to create ribbons of flavor.

Cover and freeze for at least 6-8 hours or overnight until firm.