Ingredients:

  • 1.5 cups (340g) unsalted butter, softened
  • 2 cups (400g) light or dark brown sugar, packed
  • 0.5 cup (100g) granulated white sugar
  • 5 large eggs (approx. 250g), room temperature
  • 1 tablespoon (15ml) pure vanilla bean paste or extract
  • 3 cups (375g) cake flour, sifted
  • 0.5 teaspoon (2.5g) baking powder
  • 0.5 teaspoon (3g) fine sea salt
  • 0.5 cup (120g) full-fat sour cream, room temperature
  • 4 tablespoons (56g) unsalted butter (for glaze)
  • 0.5 cup (100g) light brown sugar (for glaze)
  • 0.33 cup (80ml) heavy whipping cream
  • 1 pinch flaky sea salt
  • 0.5 cup (60g) powdered sugar, sifted

Instructions:

  1. Position oven rack in the lower third and preheat to 325°F (165°C). Generously grease a 10 or 12-cup Bundt pan with baking spray or a mixture of flour, oil, and shortening.
  2. In a stand mixer with a paddle attachment, beat the 340g butter, brown sugar, and granulated sugar on medium-high for 5–7 minutes until the texture is pale and fluffy.
  3. Add eggs one at a time, beating for 30 seconds after each addition to ensure a stable emulsion. Mix in the vanilla.
  4. Sift together cake flour, baking powder, and salt. Alternately add the dry ingredients and sour cream to the butter mixture, beginning and ending with flour. Mix until just combined; do not overmix.
  5. Pour batter into the prepared pan and smooth the top. Bake for 70–80 minutes until a skewer comes out clean or the internal temperature reaches 210°F (99°C).
  6. Prepare the glaze by melting 56g butter and 100g brown sugar in a saucepan. Whisk in heavy cream and simmer for 2 minutes. Stir in powdered sugar if using, then let cool slightly.
  7. Cool the cake in the pan for 10–15 minutes before inverting onto a wire rack. Pour the warm butterscotch glaze over the cake while it is still slightly warm.