Preheat oven to 400°F.
Line a baking sheet with parchment paper or a silpat mat and set aside.
Whisk together the dry ingredients in a large bowl: All-Purpose flour, cake flour, pudding mix, corn starch, baking powder, baking soda and salt. Set aside.
2 1/2 cups all-purpose flour, 1 1/2 cups cake flour, 1 (3.4 oz.) box Instant Vanilla Pudding Mix, 2 tsp. cornstarch, 1 tsp. baking soda, 1 tsp. baking powder, 1 tsp. salt
Chop up the fruity pebble candy bars into chunks. Set aside.
Using a stand mixer fitted with the paddle attachment, cream butter and sugar on medium speed until light and fluffy, about 3-4 minutes. Then add in the eggs, egg yolks and vanilla. Scrape sides of the large bowl as needed. 1 cup unsalted butter, cubed, cold (16 Tbsp.), 1 1/4 cup granulated sugar, 2 large eggs, 2 large egg yolks, 1 Tbsp. vanilla extract
Turn the mixer to low and gradually add in the dry ingredients, followed by 1 cup of fruity pebbles and chopped up candy bars. Mix just until ingredients are combined.
2 1/2 cup fruity pebbles, divided, 4, (2.75 oz. candy bars) Fruity Pebble Candy Bars, King Size*
Shape dough into ~8 large dough balls. Pour remaining fruity pebble cereal in a shallow bowl or dish and roll cookies in the cereal, slightly pressing cereal into the dough.
Place on prepared baking sheet and bake for ~10-12 minutes or until the edges look slightly golden.
Let cookies cool on the cookie sheet for 15 minutes and then transfer to a wire cooling rack to cool completely. Enjoy!