Line 8" square glass baking dish with foil, overlapping sides. Combine bittersweet chocolate, marshmallow creme, unsweetened chocolate and vanilla in a medium bowl. Mix water and espresso powder in a heavy large saucepan until espresso powder dissolves. Add sugar, sweetened condensed milk, whipping cream and unsalted butter and stir constantly but slowly with a wooden spoon until candy thermometer registers 234F, about 12 minutes.

Immediately pour mixture over ingredients in the bowl (Do Not Scrape Pan). Stir mixture vigorously with wooden spoon until all chocolate melts and fudge thickens slightly, about 3 minutes. Transfer the fudge mixture to the prepared baking dish. Smooth top of fudge with a rubber spatula. Refrigerate fudge uncovered until firm enough to cut, about 2 hours.

Using aluminum foil as an aid, lift fudge from pan. Trim edges of fudge. Cut into 30 pieces. Melt white cholocate in top of a double boiler over simmering water. Using a fork, drizzle white chocolate decoratively over the fudge. Press 1 espresso bean onto top of each piece of fudge. Place fudge in candy paper or foil cups. Refrigerate fudge until white chocolate sets, about 20 minutes.

Can be prepared 1 week ahead. Store in an airtight container in the refrigerator. Bring fudge to room temperature before serving.

For holiday gift giving, line small box with holiday paper. Make sure to tell recipient to refrigerate left-overs if there are any!