Step 1

Preheat oven to 350 degrees. Spread oats on a rimmed baking sheet; bake until lightly toasted but not browned, about 15 minutes. Let cool. Pulse in a food processor until coarsely chopped. Mix in 1 cup of a combination of add-ins (see our suggestions below), and stir in sugar, salt, and cinnamon, or more to taste, before storing in an airtight container for up to 2 weeks.

Step 2

To serve, stir in boiling water until desired consistency is reached. Let stand 2 to 3 minutes.