INGREDIENTS
1 stick
unsalted butter, softened
1/2 cup
sugar
1
large egg yolk
1 cup
all-purpose flour
2 1/2 tbsp
Dutch-processed cocoa powder
1/2 cup
water
2 cups
granulated sugar
1/4 cup
light corn syrup
1/2 cup
heavy cream
8 tbsp
salted butter
2 tbsp
sour cream
1/2 cup
heavy cream
4 oz
extra-bittersweet chocolate, finely chopped
Sea salt or kosher salt for garnish