In a large mixing bowl, beat the butter until fluffy. Add the brown sugar and vanilla extract; beat again. Mix in 2 cups of flour and the salt. While mixing, pour in the condensed milk and mix well, scraping the sides. Add the rest of the flour, mixing and scraping. The dough will be thick. If it’s too dry, add a little more milk, 1 tbsp at a time.

Add the peanut butter and beat on a low speed until combined. Don’t overmix. Stir in the chocolate chips by hand.

Line a 9×13” glass pan with parchment or waxed paper. Spread the dough into the pan and chill for about 1 hour. 

Melt the remaining chocolate chips and peanut butter for about 30 seconds in the microwave, stir well. Melt for 10 more second intervals, stirring well until melted.

Spread over the top of the cookie dough. Chill for a couple more hours or overnight until the chocolate is set on top. 

Spread out into a 9″x13″ brownie pan lined with greaseproof paper. Chill in the fridge for one hour. Cut and serve. Enjoy!