Preheat your oven to 350°F (175°C). Line a 9x9-inch baking pan with parchment paper or lightly grease it.
In a large bowl, whisk the melted unsalted butter with granulated sugar until smooth. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract and white miso paste until silky and well incorporated.
In a separate bowl, sift together the all-purpose flour, unsweetened cocoa powder, baking powder, and salt to avoid lumps.
Gradually fold the dry ingredients into the wet mixture carefully to keep the batter thick and fudgy without overmixing.
Pour half the batter into the prepared pan and spread evenly. Drizzle half the caramel sauce over it. Add remaining batter on top and drizzle the rest of the caramel. Use a knife or skewer to gently swirl the caramel for a marbled effect.
Bake for 30-35 minutes or until a toothpick inserted near the center comes out with a few moist crumbs. Let brownies cool completely on a rack before cutting.
Equipment
9x9-inch square baking pan
Mixing bowls
Whisk
Spatula
Measuring cups
Measuring spoons
Cooling rack
Notes
Substitute butter with coconut oil or vegan butter for a dairy-free version.
Use gluten-free flour blend for gluten-free brownies.
Store brownies in an airtight container at room temperature for up to 4 days, refrigerate up to a week, or freeze up to 3 months.