Preheat oven to 325°F and grease a mini muffin pan with non-stick spray.
In a medium microwave-safe bowl, melt the chocolate chips (1 cup) and butter until smooth. Stir the mixture every 30 seconds as you microwave them.
Whisk the sugar into the warm chocolate mixture really well (about 2 minutes) so that it dissolves as much as possible. Make sure it's cool and then mix in the eggs for another 1-2 minutes.
Gently fold in the flour, cocoa powder, salt, and mini chocolate chips with a spatula just until all flour streaks have disappeared.
Using a small/medium cookie scoop (2-3 tablespoons), fill each well of the greased mini muffin pan with brownie batter.
Bake for 12-16 minutes, or until the tops look slightly firm and start to crack a little.
Let the brownie bites cool in the pan and then remove them. If your pan was greased well, you should be able to give them a little twist and pull them right out. Otherwise, you might need to carefully scoop them out with a knife.
Video
Notes
Regular Muffin Pan: These can also be made in a regular-sized muffin/cupcake pan. If you make them this way, add 2 scoops (about ¼ cup) of batter to each well and bake them for 15-20 minutes!Measuring Dry Ingredients: Use a scale to weigh the flour for the most accurate and best results. Otherwise, scoop and level with measuring cups.Chocolate Chips: I recommend using high quality (at least 60% cocoa) chocolate chips for the ones melted into the batter.Storage: Store in an airtight container at room temperature for up to 1 week or in the freezer for up to 1 month.Nutrition: The provided nutrition information is an estimate, the calorie accuracy is not guaranteed.