While Pastry Cream is still warm, stir in powdered espresso or instant coffee. Cool with plastic wrap pressed against entire surface of cream. Warm ganache in microwave, or in small saucepan over low heat, until loose and liquid. Fold into 3 cups Whipped Cream (leave ½ cup cream unflavored). Set aside and chill at least 20 minutes.
Assemble 10 teacups (6- to 8-ounce size). Layer bottom of cups with 2 tablespoons coffee-flavored Pastry Cream. Add a layer of ladyfinger pieces, then 2 heaping tablespoons nuts. Fill remainder of cup with chocolate Whipped Cream. Serve with a dollop of plain Whipped Cream and a Pecan Puff on the side. The parfaits may be chilled for up to 24 hours before serving.