• Preheat oven to 325 Degrees F. Line standard muffin tins with paper liners. Makes about 16 standard cupcakes.
• Sift together cake flour, baking powder, and salt in a medium bowl. Set aside.
• Heat milk and vanilla-bean pod and seeds in a small saucepan over medium heat just until bubbles appear around the edge. Remove from heat. Whisk in butter until melted, and let stand 15 minutes. Strain milk mixture through a fine sieve into a bowl, and discard vanilla-bean pod.
• With an electric mixer on medium speed, whisk together whole eggs, yolks, and sugar. Set mixing bowl over a pan of simmering water, and whisk by hand until sugar is dissolved and mixture is warm, about 6 minutes. Remove bowl from heat. With an electric mixer on high speed, whisk until mixture is fluffy, pale yellow, and thick enough to hold a ribbon on the surface for several seconds when whisk is lifted. About 5 minutes.
• Gently but thoroughly fold flour mixture into the egg mixture in three batches; stir 3/4 cup batter into the strained milk mixture to thicken, then fold milk mixture into the remaining batter until just combined.
• Divide batter evenly among lined cups, filling each three-quarters full. (I use a 1/4 C measuring cup to fill each one. That way your cupcakes are all about the same size). Bake, rotating tins halfway through, until centers are completely set and edges are light golden brown, about 18 minutes. Transfer tins to wire racks to cool completely before removing cupcakes.

For the coffee syrup

• Combine sugar, strong hot coffee and rum together and stir until sugar has dissolved. Set aside to cool.

For the mascarpone frosting

• In a medium bowl whip heavy cream until stiff. In a separate bowl mix mascarpone and confectioner sugar together until smooth. Fold whipped cream into mascarpone until well combined.

To finish

• Either pierce the tops of each cupcake with a fork several times or you could cut a circle out of the center of each cupcake so that the syrup can soak into the cupcake. Brush tops of cupcakes evenly with coffee-marsala syrup; repeat until all syrup has been used. Allow cupcakes to absorb liquid 30 minutes. Dollop frosting onto cupcakes or fill a pastry bag fitted with a decorating tip and pipe the frosting onto the cupcakes. Refrigerate up to overnight in airtight containers. Remove from fridge about 30 minutes before serving. Dust generously with cocoa powder just before serving and top with coffee bean.