Lay ¾ cup M&M’s® in one even layer along the bottom of the crust as it is cooling.
While baking the crust, place packages of cream cheese in a bowl of hot water and let stand for 10 minutes. This softens the cream cheese and helps prevent lumps.
Cut open each package of cream cheese and squeeze into the stand mixer bowl. Add 1 ¼ cups of sugar and mix until smooth.
Slowly incorporate two eggs into the mixture, then add cornstarch. Add heavy cream with mixer on the lowest setting.
Pour the mixture into the crust until it reaches the top of the crust's side. It is OK if you don't use all of the mixture. However, if your sides are abnormally shallow, feel free to add additional filling.
Bake for ~50 minutes at 350 degrees, checking it periodically for doneness. The cheesecake is done while the middle is still wobbly and internal temperature reaches 150 degrees. Be careful not to over bake or it will crack and be dry.
Place cheesecake in the refrigerator for 1 hour, up to overnight, to cool.
Top with ½ cup chopped M&M’s® prior to serving and gently press into top.
Slice and serve.