My all-time favorite best brownie recipe made in a loaf pan has been oh-so-perfected over the years. As if cutting the brownies in half into two giant bakery-sized pieces isn't fun enough, I then stirred in pretty M&Ms, but other fun things to stir in or press into the surface include mini chocolate chips, your favorite chopped chocolate bar, chopped pieces of crystallized ginger (oh yes), chopped candy bars (especially the ones with caramel!) and even sprinkles!
For best results, ensure your butter, sugar, and cocoa mixture isn't too hot before adding the egg, as this can scramble it. The "50 brisk strokes" for flour incorporation is crucial to avoid overmixing, which develops gluten and can lead to tough, cakey brownies rather than fudgy ones. Always allow brownies to cool completely in the pan; this sets their structure, preventing them from falling apart when sliced and enhancing their fudgy texture. Don't be afraid to experiment with other high-quality mix-ins like dark chocolate chunks or toasted nuts for added depth.