Cream butter and sugars until smooth. Add eggs and vanilla, beating until smooth.
Combine flour, baking soda, baking powder and salt. Slowly add to mixer and mix until combined. Don't over-mix.
By hand, stir in the chocolate chips and chocolate chunks. Don't over-mix.
Using a ¼ cup spring release scoop, scoop dough onto a flat-bottom container that is lined with parchment paper or waxed paper. Place in refrigerator for 20 minutes or up to 2 days.
I used an ice cream scoop that holds exactly ¼ cup of batter. I put the Snickers on top of 1 dough ball then took another cookie dough ball (same size, 1/4 cup of batter) and smushed them together into a large ball. Then, I placed the cookie dough in a flat-bottomed container with a lid and placed them in the refrigerator for 20 minutes. You can chill the dough for up to 2 days.
When I was ready to bake the cookies, I preheated the oven to 350 degrees F. I place the balls of cookie dough on a Silpat mat on a light-colored sheet pan and baked them for 14 minutes. For me, this was the perfect doneness - the cookies were crisp around the edges with soft centers. Now, obviously, the size of your cookies determines baking time. I recommend you Calibrate your Oven at least once a year because that can also affect baking time. As well, the color of your sheet pan affects baking time. Dark pans cook faster than light pans.
Allow cookies to sit on the cookie sheet untouched for 3 to 4 minutes after removing them from the oven. After 3 to 4 minutes, using a thin spatula, transfer the cookies from the cookie sheet to a wire rack to cool.
I prefer these cookies slightly warm but set. If you try to serve them when they're too warm they fall apart because they is so much chocolate in them.