Using a hand or stand mixer, cream together butter, brown sugar and granulated sugar for about 2 minutes. Add eggs and vanilla and mix until combined.
In a separate bowl, combine flour, baking soda and salt. Add the dry ingredients to the butter mixture and mix on low until just combined. Don't overmix! Add the chocolate chips and chocolate-covered espresso beans if using.
Using a large cookie scoop (about 3 tablespoons) or small ice cream scoop, scoop cookie dough into balls and place on a baking tray or plate that will fit into the refrigerator.
If using the chocolate discs, press 1-2 discs into the top of each of the cookie dough balls.
Refrigerate the cookie dough balls overnight, covering the baking sheet/plate with plastic wrap or foil.
When ready to bake, preheat the oven to 350 degrees Fahrenheit and line a baking sheet with parchment or a silicone baking mat. Place the cookie dough balls about 2 inches apart on the baking sheet.
Bake for 12 to 14 minutes until the cookies are beginning to turn golden brown at the edges but are still just slightly underbaked in the center. Allow to cool on the cookie sheet for about 5 minutes before moving to a wire rack to cool completely.