Preheat your oven to 375 degrees F and prepare baking sheets by lining with parchment paper.
Combine flour, baking soda and salt, then set aside.
Combine butter and sugar and mix with an electric mixer. Add the egg, yogurt, dry pudding mix, then mix together until smooth.
Pour dry ingredients into the mixing bowl with butter mixture and mix slowly until incorporated.
Divide dough into 3 sections. Add drops of color to each section as well as a few tablespoons of sprinkles and 2/3 cups of the chocolate chips. Stir gently but thoroughly, so that color is even and sprinkles are well distributed.
Scoop rounded tablespoonfuls of cookie dough onto parchment lined baking pan.Bake at 375 degrees F for 10 minutes. Let Funfetti Halloween Cookies cool for several minutes on the cookie sheet before transferring to a cooling rack.