Jersey Black Butter Swirl Ice Cream Cake Roll

**Sponge Cake:** Preheat oven to 200°C (180°C fan/Gas Mark 6). Grease and line a 33x23cm (13x9 inch) baking sheet with parchment paper.

In a large bowl, whisk together the eggs and sugar until pale and fluffy. This will take about 5-7 minutes using an electric mixer.

Gently fold in the sifted flour and baking powder, being careful not to overmix.

In a small bowl, combine the melted butter and milk. Gently fold this mixture into the batter.

Pour the batter onto the prepared baking sheet and spread evenly. Bake for 10-12 minutes, or until golden brown and springy to the touch.

Remove from the oven and let cool slightly in the tin for a few minutes.

Dust a clean tea towel with icing sugar. Carefully invert the cake onto the tea towel. Peel off the parchment paper. Roll up the cake tightly in the tea towel and let it cool completely. This will help it keep its shape for the final roll.

**Jersey Black Butter Ice Cream:** In a saucepan, gently heat the Jersey milk, double cream, and caster sugar over medium heat, stirring until the sugar is dissolved. Do not boil.

Remove from the heat and stir in the vanilla extract (if using) and the mashed Jersey Royal potatoes.

Let the mixture cool completely, then chill in the refrigerator for at least 4 hours, or preferably overnight.

Churn the chilled mixture in an ice cream maker according to the manufacturer's instructions. If you don't have an ice cream maker, pour the mixture into a freezer-safe container and freeze for 2-3 hours, stirring every 30 minutes to prevent ice crystals from forming.

Once the ice cream is churned or partially frozen, gently fold in half of the Jersey Black Butter, creating a marbled effect.

**Assembly:** Unroll the cooled sponge cake carefully.

Spread the Jersey Black Butter ice cream evenly over the cake, leaving a small border at the edges.

Drizzle the remaining Jersey Black Butter over the ice cream layer.

Carefully roll the cake back up tightly, starting from one end. Wrap the roll tightly in plastic wrap and freeze for at least 2 hours to allow the ice cream to firm up.

**Serving:** Remove the ice cream cake roll from the freezer about 10 minutes before serving. Slice into portions and garnish with fresh Jersey seasonal fruit, if desired. Serve with extra Jersey Black Butter on the side, if you like.