1/4 cup
(57 grams) unsalted butter, cold, cubed, plus more for the pan
3 cups
(384 grams) all-purpose flour, plus more for the pan
2 cups
(400 grams) granulated sugar
1 tablespoon
baking powder
1 1/2 teaspoons
kosher salt
1/4 teaspoon
ground turmeric
3/4 cup
(145 grams) canola oil
4 1/2 teaspoons
vanilla extract
2
large eggs
2
large egg yolks
2 cups
(467 grams) buttermilk, room temperature
3/4 cup
(170 grams) unsalted butter, melted and cooled slightly
1 cup
(85 grams) natural cocoa powder
1 1/2 teaspoons
vanilla extract
3/4 teaspoon
kosher salt
4 1/2 cups
(513 grams) powdered sugar
1/2 cup
strong, cold coffee, plus more as needed