01 -
Preheat oven to 175°C. Line an 18x33 centimetre half sheet pan with parchment paper or grease thoroughly.
02 -
Melt 227 grams butter and 240 millilitres water in a medium saucepan over medium-high heat. Add 400 grams brown sugar and bring to a rolling boil, stirring occasionally. Remove from heat.
03 -
Allow the mixture to cool for several minutes, then add 2 teaspoons vanilla. Sift 250 grams flour on top, then sprinkle with 0.5 teaspoon salt and 1 teaspoon baking soda. Gently stir the salt and baking soda into the flour before whisking to combine, ensuring a smooth batter.
04 -
Whisk 2 large eggs with 120 grams sour cream in a separate bowl. Add this mixture to the batter and stir until fully incorporated.
05 -
Spread the batter evenly in the prepared pan. Bake for 17–20 minutes until a toothpick inserted in the centre comes out clean and edges pull away from the sides. Cool for approximately 20 minutes before icing.
06 -
In a clean saucepan, melt 170 grams butter, 770 grams brown sugar, 200 millilitres evaporated milk or heavy cream, and 0.25 teaspoon salt over medium heat. Bring to a rolling boil, stirring constantly until the icing thickens to coat the back of a spoon. Remove from heat and add 1.5 teaspoons vanilla.
07 -
Place the saucepan of icing into a large bowl of ice water, taking care not to allow water into the caramel. Stir constantly for 3–5 minutes, scraping the sides, until the icing begins to set but remains pourable.
08 -
Pour the caramel icing evenly over the slightly cooled cake. Spread to the edges. Let set for several minutes before serving, warm if desired.