01 - Preheat oven to 350°F. Grease and line an 8x8-inch baking pan with parchment paper.
02 - In a large mixing bowl, whisk melted butter and sugar until smooth.
03 - Add eggs and vanilla extract to the bowl, whisking until well combined.
04 - Pour in milk and whisk until ingredients are fully blended.
05 - In a separate bowl, sift together sweet rice flour, cocoa powder, baking powder, and salt.
06 - Gradually fold the dry mixture into the wet ingredients, stirring until a smooth batter forms.
07 - Gently fold in chocolate chips and nuts if desired.
08 - Pour batter into the prepared pan and smooth the surface evenly.
09 - Bake for 35 to 40 minutes, until the top is set and a toothpick inserted in the center yields a few moist crumbs.
10 - Let brownies cool completely in the pan before cutting into squares for the optimal chewy texture.