Preheat oven to 350℉
Line a 13x9 baking pan with aluminum foil or parchment paper
In a mixing bowl, stir flour and baking soda together. Set aside.
In a separate mixing bowl, add butter and sugars. With a stand or handheld mixer, mix on medium until creamed together.
To the sugar mixture, add the eggs and vanilla. Mix on low until fully combined.
Scrape the sides of your bowl well with a spatula. Add half of your flour mixture. Mix on low until the flour is combined. Repeat with the remaining flour.
Add ½ cup of M&M candies and fold in carefully with a spoon or spatula.
Add dough to your prepared 9x13 pan. Spread the dough evenly in the pan. The dough will be very sticky. You can lightly spray your hands with a nonstick spray.
Top with remaining M&M candies and sprinkles
Bake for 18-20 minutes
Immediately after removing the pan from the oven, gently place the chocolate Easter bunnies and mini Robin Eggs on top. Lightly press them into the dough and allow to cool completely before slicing and serving.