Swedish Tiger Cake (Tigerkaka)

Name: Swedish Tiger Cake (Tigerkaka)
Prep time: 20 min
Cook time: 1 h 30 min
Total time: 1 h 50 min
Cuisine: European
Ingredients: ⅓ cup cocoa powder; ½ teaspoon espresso powder (optional); ⅓ cup sugar; ¼ cup warm water; 2 ½ cups all-purpose flour; 2 teaspoons baking powder; 1 ½ cups granulated sugar; ¾ cup canola or vegetable oil; 2 teaspoons pure vanilla extract; ¾ teaspoon fine salt; 3 large eggs + 1 egg yolk; ¾ cup buttermilk