Jersey Milk and Black Butter Swirl Brownies

Preheat oven to 350°F (175°C). Grease and flour an 8x8 inch baking pan.

In a heatproof bowl set over a saucepan of simmering water (double boiler), melt the butter and chopped chocolate together, stirring occasionally until smooth. Remove from heat.

Stir in the sugar into the melted chocolate mixture until well combined. Let it cool slightly.

Beat in the eggs one at a time, then stir in the vanilla extract.

In a separate bowl, whisk together the flour, cocoa powder, and salt.

Gently fold the dry ingredients into the wet ingredients until just combined. Do not overmix.

In a small bowl, combine the mashed Jersey Royal potatoes and the Jersey milk, whisk to combine and set aside. Be careful not to add too much potato as this will change the texture

Pour half of the brownie batter into the prepared pan.

Dollop teaspoons of the Jersey milk mixture and the black butter evenly over the batter. Gently swirl them into the batter using a knife or toothpick.

Pour the remaining brownie batter over the top and repeat the process of dolloping and swirling the Jersey milk mixture and the black butter into the top layer.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached. Be careful not to overbake.

Let the brownies cool completely in the pan before cutting into squares.