Preheat the oven to 350F and line two cookie sheets with parchment paper or silicone mats.
Mix the flour and baking soda in a bowl and set aside.
Cut the cold butter into 1-inch bits and mix in a stand mixer with a paddle attachment. Add in the sugar and mix until it's light and fluffy. Beat in the egg and extract.
Gradually add in the flour 1 cup at a time until it's just combined. Scrape down the sides of the bowl. The mixture will be thick and crumbly.
Transfer the dough to a large piece of plastic wrap. Cover it with a second piece of plastic wrap and press/roll out to ⅛" thickness. Cut out your shapes and place them on to the cookie sheet. Place them into the freezer for 15 minutes, then bake for 9-12 minutes. Cool on the sheet for two minutes then transfer to a cooling rack.
When all the cookies are baked and cooled, it's time to decorate.
To decorate the cookies
Spread a thin layer of your base icing. You can outline the cookie and fill it in or use an offset spatchula to spread it. Allow the cookie icing to completely dry for 2 -3 hours.
If you are coloring your cookie icing, add some to a bowl and add just a drop of the food coloring and stir until desired color is obtained.
When the cookies are dry, outline the cookie and add any designs now. Pour the sprinkles over the wet icing and shake off the excess. The sprinkles should just stick to the wet icing. Set the cookie aside to completely dry. Overnight is best.
For the Ducks
Fill with yellow cookie icing on the body and orange icing on the bill. Dry.
Add blue icing to the bottom and add blue crystals. Dry.
Outline with yellow and add three lines for the wings. Cover with yellow crystal and dry.
For the Carrots
Fill with orange cookie icing and dry.
Outline with orange icing and coat in orange crystals. Pipe on green and cover in green crystals. Dry.
For the Bunnies
Fill with white cookie icing and dry.
Outline with icing and add sprinkles. On the leaping bunny, I used Cake Mate Classic Pearls and on the sitting bunny I used Cake Mate Nonpareils in Polka Dots. Use half a mini marshmallow or a Cake Mate Easter Egg decor for the tail.