1. Heat oven to 400 degrees F. In saucepan, bring milk, butter, sugar and salt to a boil over medium-high to high heat. Add flour all at once; stir until ball forms and pulls away from sides of pan; cook, stirring constantly, 1 minute. Remove from heat; transfer to a bowl. Let cool 5 minutes, stirring occasionally.
2. Add eggs, one at a time; after each addition, beat well with wooden spoon or electric mixer set on low speed. When all eggs are added, beat well until mixture is shiny and smooth, about 1 minute. Spoon into large pastry bag without a tip. Pipe 12 puffs, about 3 inches in diameter, onto ungreased baking sheet.
3. Bake at 400 degrees F for 15 minutes, then reduce heat to 350 degrees F and bake an additional 15 minutes until puffed and golden. Turn oven off; place baking sheet on a wire rack. Remove puffs from sheet; poke a small hole in the bottom of each puff. Place upside down on baking sheet; return to oven and let sit 10 minutes with door slightly ajar (this will help dry out moist inner dough). Remove to a wire rack; cool completely.
4. In a large bowl, combine heavy cream and coffee granules. Let sit 5 minutes. Add 2 tablespoons of the chocolate sauce. Beat with an electric mixer or by hand until medium-stiff peaks form.
5. Cut puffs in half horizontally. Remove any moist dough from centers. Spoon whipped cream into puffs, about 2 heaping tablespoons each. Replace tops of cream puffs. Drizzle plates with remaining chocolate sauce; place puffs on top. Dust with confectioners sugar. Serve immediately.