Preheat the oven to 400°F and line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt.
Add the cold butter to the bowl and use a pastry cutter or your fingers to cut the butter into the flour mixture until it resembles coarse crumbs.
In a separate bowl, whisk together the milk, egg, and vanilla extract.
Add the wet ingredients to the dry ingredients and mix until just combined.
Gently fold in the Fruity Pebbles cereal.
Turn the dough out onto a floured surface and knead a few times until it comes together.
Pat the dough into a circle about 1 inch thick and cut into 8 wedges.
Place the scones on the prepared baking sheet and bake for 15-18 minutes, or until lightly golden brown.
Allow the scones to cool for a few minutes before serving. Enjoy!