How to Make It
Using an electric mixer fitted with a whisk attachment, beat heavy cream, mascarpone, powdered sugar and molasses on medium, scraping the bottom of the bowl once, until medium peaks form, 3 to 4 minutes.
Pour coffee into a shallow bowl. Working one at a time, dip the ladyfingers in coffee until soaked but not soggy, about 2 seconds per side. Place 12 into an 8x8-inch square baking dish to form an even layer, breaking to fit as necessary. Spread half of the mascarpone mixture evenly over the ladyfingers. Repeat with remaining ladyfingers and mascarpone. Cover with plastic wrap and refrigerate until firm, about 4 hours. Dust with cocoa powder before serving.