Combine oat milk, coconut milk, and maple syrup in a medium saucepan over medium heat. Warm gently until steam rises but do not boil (about 4–6 minutes), stirring to dissolve the syrup.

In a small bowl, whisk together the soy/pea protein powder, lecithin, oil, vanilla, and salt until smooth. This helps incorporate fat and stabilizers for creaminess.

If using the optional cornstarch stabilizer: mix the cornstarch with the cold water to make a slurry and whisk it into the warmed milk mixture now. Continue to cook and stir for 1–2 minutes until the mixture slightly thickens.

Remove the saucepan from heat. Whisk in the protein/lecithin mixture until fully combined and smooth. Taste and adjust sweetness or vanilla as desired.

Cool the mixture to room temperature: transfer to a clean container, cover, and place in the refrigerator for at least 3 hours or overnight. Chilling improves texture and helps the machine freeze the mix evenly.

Once thoroughly chilled, strain the mixture through a fine-mesh sieve into the hopper of your soft-serve machine or into a blender if using a countertop soft-serve maker to remove any lumps.

Follow your machine's instructions to freeze and aerate the mixture into soft serve. Typical machine run time is 15–25 minutes depending on model; you want a light, scoopable but soft texture.

Serve immediately for classic soft-serve texture. If you need to hold the soft serve, keep it in the machine's freezer chest at recommended temperature or transfer to a shallow, airtight container and freeze for up to 2 hours (the texture will firm slightly).

Customization & Serving

Fruit swirl or flavored base

If adding fruit puree or other flavorings, fold or swirl them into the chilled base just before pouring into the machine. For chocolate, whisk cocoa powder with 1–2 tablespoons warm milk from the recipe to make a smooth paste, then mix into base.

Coffee or matcha

Stir concentrated espresso or dissolved matcha into the chilled base. Ensure powders are fully dissolved to avoid gritty texture.

For toppings and mix-ins (nuts, cookie crumbs, sauces): offer them on top of the dispensed soft serve or run small amounts through the machine's mix-in chute if your equipment supports it. Add delicate toppings after dispensing to maintain crunch.

To create cones or sundaes: dispense into chilled cones or bowls. Garnish with sauces, fruit, sprinkles, or vegan whipped cream as desired.

Storage note: Unused chilled base can be stored in the refrigerator for up to 3 days. Once frozen into soft serve and held, quality is best consumed the same day.