Pre-cook the flour for the cookie dough. Simply place the flour on a parchment lined cookie sheet and bake for five minutes at 350˚F. Cool completely. (Lift and fold the parchment paper to easily pour the flour into the remaining ingredients.)
Cookie Dough: In a large bowl using a handheld mixer or stand mixer with the paddle attachment, beat the butter, brown sugar, and white sugar together on medium speed until light and creamy. Add the milk and vanilla. Mix. Add the flour and salt all at once and slowly mix until everything is moist. Add the mini chocolate chips. Mix.
Roll cookie dough into several long ropes about ½-inch thick and place on a baking sheet. Place baking sheet in the freezer for about 30 minutes. Then remove the baking sheet from the freezer and slice into bite size pieces, about ½-inch wide. Keep cold. If necessary, return cookie to the freezer while prepping the next step.
Ice Cream: In the bowl of a stand mixer with the whisk attachment, whip the heavy cream until stiff peaks, about 3½ minutes on high speed.
Mix together the condensed milk and vanilla in a large bowl. GENTLY fold in the whipped cream until no white streaks appear, being careful not to deflate the mixture too much.
Using a 2 quart container, pour ⅓ of the ice cream mixture. Sprinkle with cookie dough pieces and drizzle with slightly warm hot fudge. (About 30 seconds in the microwave; just enough to drizzle or squeeze from a zip-top bag with the corner cut off.)
Pour another ⅓ of the ice cream mixture; sprinkle with cookie dough pieces and drizzle with hot fudge.
Pour the last ⅓ of the ice cream mixture. Sprinkle with cookie dough pieces and drizzle with hot fudge.
Freeze 6 hours or until firm; freezing overnight is good. Store in the freezer.