½ cup buttermilk – warmed
¼ cup espresso
1 ⅓ cup sugar – divided
1 (7g) packet active dry yeast
2 eggs
1 tsp vanilla extract
½ tsp salt
3 ¼ cups all-purpose flour
½ cup butter – softened and cubed
½ cup unsalted butter – melted (plus 2 Tbsp for brushing)
5 Tbsp Kahlua – divided
16 oz mascarpone – softened and divided
2 cups powdered sugar
1 tsp cinnamon
2 ½ cups cream
For serving: Cocoa powder