How to Heat-Treat Flour: Place 1 cup of all-purpose flour in a large microwave-safe bowl and cook on high in the microwave for 1 minute. Remove the bowl from the microwave, stir the flour with fork, and return it to the microwave to cook on high for an additional 1 minute. Put that fork in the sink to wash as you don’t want to reuse it with raw flour on it. Remove bowl from microwave and check temperature using an instant-read thermometer. The temperature of the flour should be 175°F or higher. If not yet 175°F, place the flour back in the microwave for another minute on high heat, then check again. Pour all heated flour into a fine-mesh sieve and sift into a new bowl. Use a spoon to push any chunks of flour through the strainer. There will be a few hardened pieces (looks like rice) left in the strainer – throw those pieces away.
1 cup heat-treated all-purpose flour
In a small bowl, microwave ¼ cup of the chocolate chips until melted. Start with 1 minute on high, then remove the bowl from the microwave and stir well. Continue heating in 30-second intervals (stirring between intervals) until the chocolate is melted.
¾ cup semisweet chocolate chips
In a large bowl, using a hand mixer, beat the butter, brown sugar, granulated sugar, vanilla extract, and melted chocolate together until well mixed, about 2 minutes.
½ cup unsalted butter, ¾ cup brown sugar, ¼ cup granulated sugar, 1 teaspoon pure vanilla extract
Beat in the heat-treated flour, cocoa powder, salt, and milk until fully combined, about 1 minute. Use a rubber spatula to scrape down the sides of the bowl.
½ cup unsweetened cocoa powder, ¼ teaspoon kosher salt, 2 tablespoons milk
Stir in the remaining ½ cup of chocolate chips.
(Optional) Roll the brownie batter into equally-sized balls for an on-the-go treat.