Ingredients:

  • 1.5 cups (225g) black raspberries
  • 0.25 cup (50g) granulated sugar
  • 1 tbsp (15ml) lemon juice
  • 1 tsp (3g) cornstarch
  • 1 tbsp water
  • 1 cup (225g) unsalted butter, softened
  • 1 cup (200g) granulated sugar
  • 3 large (150g) eggs, room temperature
  • 1 tsp (5ml) pure vanilla extract
  • 2 cups (250g) all-purpose flour
  • 0.5 tsp (3g) baking powder
  • 0.5 tsp (3g) salt
  • 0.5 cup (120g) full-fat sour cream, room temperature
  • 1 cup (120g) powdered sugar
  • 2 tbsp reserved black raspberry reduction
  • 1 tbsp (15ml) heavy cream

Instructions:

  1. Combine black raspberries, sugar, and lemon juice in a saucepan over medium heat.
  2. Simmer for 8–10 minutes, mashing the berries with a fork until the mixture thickens.
  3. Stir in the cornstarch slurry and boil for 1 minute until glossy.
  4. Remove from heat and let cool completely.
  5. Beat the softened butter and sugar on medium-high for 3–5 minutes until the mixture is pale and fluffy.
  6. Add eggs one at a time, beating well after each addition. Stir in the vanilla extract.