Using an electric mixer cream together the butter, brown sugar, granulated sugar and vanilla. Beat for 2 minutes until fluffy and light beige in color.
Add the eggs one at a time beating well after each addition. Stop and scrape the side of the bowl as needed.
In a medium-size mixing bowl sift together the flour, pudding mix, cocoa powder, baking powder, baking soda and salt.
Lower the speed of the mixer and gradually add the dry ingredients to the creamed butter. Once all is added beat for 30 seconds or until fully incorporated.
Fold in the chocolate chunks by hand until evenly distributed in the dough.
Place into an airtight container and chill for 2 hours or overnight.
To bake preheat the oven to 375°F. Line 2 baking sheets with parchment. Roll the cookie dough in 1 ½-inch balls and arrange on the baking sheet leaving at least 2-inches between each dough round. Using the palm of your hand flatten the centers.
Bake for 10-12 minutes. Cool on the baking sheet for 5 minutes then remove to a cooling rack to cool completely.
Store tightly sealed at room temperature.