Cream the butter and sugar together. Beat in the egg and vanilla.
Add the baking soda, pudding mix, and one cup of flour and mix until combined. Add the other cup of flour.
Once everything is combined, mix in the sprinkles.
Roll the dough into about one-inch balls and place them about one inch apart on a baking sheet. Press a few extra sprinkles into the top of each cookie.
Bake for 8 to 10 minutes or until the cookies are set (they won't really brown on top). Let them cool for a bit on the cookie sheet before transferring them to an airtight container.