This dairy-free ube cookies and cream ice cream is smooth, colorful, and full of classic cookie flavor. It makes a memorable frozen treat for any occasion.
Combine the grated purple yam, coconut milk, 3/4 cup oat milk, cane sugar, coconut oil, and sea salt in a saucepan. Simmer gently for 12 to 15 minutes, stirring frequently, until the purple yam is completely tender.
Blend the cooked ube mixture until very smooth. Whisk the cornstarch with the remaining 1/4 cup oat milk, then add it to the blended mixture.
Return the ube base to medium heat and cook for 2 to 3 minutes, whisking constantly, until lightly thickened. Stir in the ube extract and vanilla, then refrigerate for at least 4 hours.
Crush the chocolate sandwich cookies into bite-size pieces and toss them with the coconut oil. Freeze the cookie pieces for at least 20 minutes.
Churn the cold ube base according to the ice cream maker's directions. Add three-quarters of the frozen cookie pieces during the final 2 minutes.
Transfer the ice cream to a freezer-safe container and scatter the remaining cookies over the top. Freeze for 4 to 6 hours, then soften briefly at room temperature before scooping.