1. Combine milk beverage, 3/4 cup sugar, cocoa butter, oil, vanilla, and salt in a blender. Blend until smooth and creamy, about 2 minutes. Add xanthan gum and blend for 1 minute.
2. Refrigerate the blender jar for at least 4 hours, or preferably overnight.
3. Puree raspberries and remaining 6-8 tablespoons sugar, to taste, in a blender until relatively smooth, about 1 minute.
4. Strain the puree through a fine-mesh sieve into a small saucepan, extracting all raspberry sauce but leaving seeds behind.
5. Bring the sauce to a boil over medium heat. Reduce heat and simmer, whisking often, for 3-4 minutes, or until it reaches a thick, syrup-like consistency. Transfer the sauce to a container, cover, and refrigerate until ready to use.
6. Whisk together softened butter and honey in a medium bowl until smooth. Stir in cracker crumbs until a crumbly dough forms.
7. Line an 8-inch square pan with parchment paper or plastic wrap, overhanging at least two opposing sides.
8. Press the crust mixture into the prepared pan to form an even layer. Freeze the crust until ready to use.
9. Blend the cold ice cream mixture until smooth. Freeze according to your ice cream maker's instructions.
10. Spread the ice cream evenly over the crust. Drizzle the raspberry puree over the ice cream and swirl it in. Freeze until solid, about 3 hours.
11. Loosen the ice cream around the edges of the pan using a knife. Lift the dessert out using the parchment or plastic wrap and place it on a cutting board. Slice into 9 even bars. Keep frozen until ready to serve.