Preheat the oven to 350 F. Line a 12 cup muffin pan with paper liners. In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with sugar until fluffy.
Add in the egg and vanilla extract, and mix until smooth. Add in the flour mixture, and mix until it is fully combined. Fold in the white chocolate chips, and fruity pebbles cereal.
Evenly divide the cookie dough between the prepared muffin pan. Bake for 12-15 minutes.