Costco replaced the mint chocolate sundae with a caramel churro version and the internet is divided — but your kitchen doesn't have to be. Creamy vanilla soft serve drowned in salted caramel sauce with crispy mini churro bites on top. Every spoonful is crunchy, gooey, salty-sweet perfection.
Make the churro dough: In a saucepan over medium heat, bring 1 cup water, 1 stick unsalted butter, and 1/2 tsp salt to a light simmer. Stir in 1 cup all-purpose flour quickly until a smooth dough forms, pulling away from the sides.
Cool the dough for 5 minutes, then beat in 2 large eggs one at a time until glossy and pipeable. (Copycat tip: This classic choux-like technique gives the churros their soft, airy interior like Costco's.)
Heat 3 cups canola oil in a heavy pan to 375°F. Pipe 2-inch strips of dough into the oil, fry in batches for 2–3 minutes, and turn until golden brown and crisp. Drain well.
While the churros are still hot, toss them in a mixture of 1/2 cup granulated sugar and 2 tsp ground cinnamon until all sides are coated generously. (Copycat tip: Coating warm provides that signature Costco sweet crust.)
Assemble each sundae: Scoop 1 cup nonfat vanilla frozen yogurt into a large bowl or cup. Pile on 3–4 warm churro bites, drizzle with 1/4 cup caramel sauce, and finish with a sprinkle of extra cinnamon sugar if desired. Serve immediately for maximum crunch against creamy soft serve!