In a large pan with high sides or pot over medium heat, melt ¼ cup butter. It's best to use a stainless steel pan or a with a light-colored bottom so you can tell when the butter has browned.
Once the butter has melted, start swirling the pan and stirring occasionally. The butter will become foamy and start making popping noises. Continue swirling and stirring the pan to keep the butter from burning until the butter has a noticeably nuttier fragrance and brown bits start to form at the bottom.
Make Matcha Rice Krispies Treats
Once the butter has browned, reduce heat to low. Add 10-ounces of marshmallows. Stir until marshmallows are completely melted.
Add 1½ tablespoons matcha powder, 1 teaspoon vanilla extract, and ½ teaspoon sea salt. Stir until matcha has been thoroughly combined into the marshmallows.
Turn off burner and remove pan from heat. Add 5 cups of rice kripsies cereal. Stir until cereal is completely coated.
Transfer the mixture into the prepared baking pan. Press down lightly with a silicone spatula into an even layer. Allow to cool to room temperature before cutting into squares.
Nutrition information estimate based on recipe cut into 9 squares.Matcha Rice Krispies can be stored in an airtight container at room temperature for up to 2 days.