Using a food processor, blend the fruity pebbles into a fine crumb. Set aside. In a medium bowl, sift the flour. Add the baking powder, baking soda, and salt.
½ cup Fruity pebble crumbs, 2 ¼ cups All-purpose flour, ½ teaspoon Baking powder, ½ teaspoon Baking soda, 1 teaspoon Salt
In a large bowl, mix the melted butter (it needs to be cooled to room temperature before using to avoid over spreading), brown sugar, sugar, vanilla, and eggs. Whisk until smooth.
1 cup Unsalted butter, ¾ cup Brown sugar, ¾ cup White granulated sugar, 1 teaspoon Pure vanilla extract, 2 Large eggs
Add in the dry ingredients and the fruity pebble crumbs. Use a rubber spatula to mix until just combined. Add the fruity pebbles and white chocolate chips.
1 cup Fruity pebbles, 1 cup White chocolate chips
Preheat the oven to 350°F. Line two cookie sheets with parchment paper. Let the cookie dough rest for 10-15 minutes while the oven preheats. This allows the gluten to absorb into the dough.
Pour some fruity pebbles into a bowl. Use a large 3 Tablespoon scoop to scoop the cookie dough. Roll each cookie dough into the fruity pebbles then place 6 cookie dough balls per cookie sheet.
Bake for 13-15 minutes until the edges of the cookies are lightly golden and middles are slightly underdone. When the cookies are straight out of the oven, top with extra fruity pebbles and top with extra white chocolate chips.
Cool the cookies on a cooling rack.