Preheat your oven to 350 degrees Fahrenheit to heat treat your flour. Spread 8 cups of all-purpose flour on a parchment-lined baking sheet. Bake the flour for 5 to 7 minutes, stir once halfway through, and check that the flour reaches at least 165 degrees Fahrenheit with a kitchen thermometer. Let it cool completely.
Place the flour in a large mixing bowl or tub. In a separate container, stir the gel food coloring into the vegetable oil until the ingredients are fully blended. If you plan to use more than one color, divide the oil evenly before adding the different food colorings.
If you’re making more than one color, scoop the flour into separate bowls. Drizzle the colored vegetable oil over the flour. Use your hands to mix it in, squeezing and rubbing until the flour feels like soft, damp sand that can hold its shape when you press it together.
If the moon sand feels too dry, add a splash more oil and remix it. If it’s too wet, sprinkle in a little more flour.
Transfer your moon sand to a shallow bin or tray. Kids can mold it into fun shapes, scoop it, or use cookie cutters to make fun designs.