Preheat the oven to 350°F and line an 8×8 pan with parchment paper or foil and lightly grease. Set aside.
In a medium sized bowl over low heat, melt the butter. Add in the sweetened condensed milk and stir with a whisk. Add in the dark chopped chocolate and continue mixing until everything is smooth and melted. Remove from heat and set aside.
3/4 cups butter, 14 oz sweetened condensed milk, 3/4 cups dark chocolate
In a large bowl, beat the eggs, egg yolk, vanilla, red food colouring (as needed) and both sugars. Whisk vigorously for 2 minutes until light and airy. There should be bubbles forming. I recommend an electric mixer for this part to save elbow grease!
1/4 cup brown sugar, 1/4 cup white sugar, 2 tbsp vanilla, 2 eggs, 1 egg yolk, red gel food colouring
Add in the chocolate mixture from earlier and gently fold together using a spatula. Do not use a whisk or overmix!
Add in the flour and unsweetened cocoa powder and continue mixing until no streaks appear.
1/2 cup all-purpose flour, 1/4 cup cocoa powder
Toss in the chocolate chips and mix for a few seconds.
1/4 cup semi-sweet chocolate chips
Pour into a prepared 8×8 square pan and spread out evenly. Bake for 20-35 minutes or until a toothpick inserted comes out sticky. The sides will be set, but inside will remain jiggly. In some ovens it takes 20 minutes, and others it takes 35, so keep an eye on it after 20! Once it's ready, turn off your oven.
Slightly open the oven door for 10 minutes and allow the hot air to come out. Then completely remove the brownies from the oven and cool on the counter. Top off with chocolate hearts, chocolate chips, and flakey sea salt.
These brownies are best eaten the day they're made. Keep any leftovers in an airtight container at room temperature for up to three days. My favourite way to eat them is warm with a scoop of vanilla ice cream!
1/4 cup semi-sweet chocolate hearts, flakey sea salt