Preheat the oven to 350°F (176°C) and line baking pans with parchment paper or silicone baking sheets. This recipe yields 5 dozen cookies, so you might need to reuse pans. Let the pan cool back to room temp before putting cookie dough on it. (I put the warm pan in the refrigerator for a few minutes to speed up the cooling process.)
Whisk together the flour and baking soda in a medium bowl.
In a large bowl cream the butter, peanut butter and sugars until light and mostly smooth. Cream in the pudding mix.
Beat in the eggs and yolk, one at a time, until fully incorporated. Mix in the extracts.
On low speed, gradually stir in the flour mixture until just combined. Fold in the sprinkles.
Drop spoonfuls of dough that are about 1.5 inches in diameter on the prepared pans, spacing them a few inches apart (no more than 12 cookies per pan). Lightly press down on each dough ball to flatten it slightly.
Bake for 8 to 12 minutes, or until the edges are lightly browned. The middles should be a little soft but not wet and doughy. Let the cookies rest on the pan for 5 minutes before transferring them to a wire cooling rack.
Store in an airtight container. Enjoy!