Combine the flour, baking soda and salt in a medium bowl. Beat the butter, sugars and molasses in a large bowl with a wooden spoon until the sugar is dissolved (the mixture shouldn't feel grainy when you rub some of it between your fingertips). Stir in the vanilla and then the milk. Add the flour mixture all at once and stir just until the dough comes together. Stir in the chocolate and the rice cereal. Cover the bowl with plastic wrap and chill for at least 30 minutes or overnight.
Position the racks in the upper and lower thirds of the oven and preheat the oven to 350 degrees F. Line baking sheets with parchment paper or silicone mats.
Roll the dough into 1 1/2-inch balls (using a cookie scoop or an ice cream scoop helps you get perfectly uniform cookies). Place the dough balls on the lined baking sheets, leaving 3 inches of space between them (about 6 cookies should fit on a large baking sheet). Flatten the balls slightly with a spatula.
4. Bake until the cookies are golden brown around the edges, 14 to 18 minutes. Let cool for about 5 minutes, then transfer the cookies with a spatula to a wire rack to cool completely.
To make sure the cookies bake evenly, switch the position of the baking sheets (meaning move the cookies on the upper rack to the lower rack and vice versa) and rotate the sheets from front to back halfway through the baking time.
How to chop chocolate: Use a sharp chef's knife on a clean cutting board. Let the chocolate fall naturally into chunks and then chop slowly so you do not overchop the chocolate resulting in lots of small shavings.