Cream softened butter in mixer, 1 minute. Add both white and brown sugar and cream well, scraping down sides often for 2 minutes.
Mix in eggs, one at a time, cream 1 minute each and scrape down sides in between. Pour in vanilla and mix well.
While creaming butter and sugar mixture; in a medium bowl, mix together flour, baking soda and salt gently with a whisk. With mixer on low or stir, slowly pour in ½ cup of flour mixture at a time and gently mix, add water in between flour mixing, don’t over mix.
Once mixed well, scrape sides of bowl and pour in chocolate chips and chunks, mix on low, until combined. By hand, stir in the M & M's into the batter.
Generously grease a 9-10" heart shaped form or pan and place on cookie sheet lined with parchment paper. May use smaller pans, just reduce baking time.
Measure out enough batter to fill the shaped pan, about ¾" thick, using a sheet of wax paper or plastic wrap, make sure it is spread evenly and to the edges. Freeze for 30 minutes.
About 15 minutes into freezing, preheat oven to 350 degrees. Remove heart shapes from freezer and place in preheated oven.
Bake 15-25 minutes (watch closely, depending on the size of your pan and the amount of dough you placed in the pan will determine how long it will take to bake.) It should be golden at the edges, starting to pull away with the center still looking slightly underdone.
Remove from oven when edges are slightly browned and center is set, but will probably still be pretty gooey. If desired, sprinkle another handful of M & M's over the top of the hot cookie.
Allow to cool on a cooling rack for 15-30 minutes if using a pan or fully on cookie sheet if using a form.
When ready to release from form or pan, take a table knife and gently run around the edges of the cookie, separating from the pan. Lift off form and allow to continue to cool completely.
If using a pan, place a cooling rack over the top of the pan and carefully invert onto cooling rack. Do the same thing again with another cooling rack if you prefer not to have rack marks on the cookie. Cool completely.
If needed to move to a serving plate, freeze for 15 minutes, then use a large spatula to transfer to plate.
Notes
Makes 2 large cookie hearts, if preferred, make one heart and approximately 16 additional chocolate chip cookies.
Scoop into balls using a medium-sized scoop onto a parchment-lined cookie sheet, 2 inches apart.
Place in fridge (or freeze until ready to bake) 10 minutes prior to baking; bake at either 350° F (175° C). (375° high altitude (190° C) 8-10 minutes until just set and slightly golden.
Cool on pan 2-3 minutes and then remove to a cooling rack to cool completely.
Enjoy warm or room temp. If not enjoying all the cookies at once, freeze dough balls until firm, then place in a freezer Ziplock bag until ready to use.
Once ready to bake, take it out of the freezer and place 2 inches apart on parchment-lined baking sheet. Let soften while the oven preheats. Bake as directed above. Always fresh cookies