Heat oven to 425°. Lightly grease a cookie sheet.

In a medium saucepan, heat water and butter to a rolling boil.

Reduce heat to low, add flour, and stir/whisk vigorously about 1 minute, or until mixture leaves the side of the pan and forms a ball. Remove from heat.

Stir in eggs, one at a time, mixing well after each addition until smooth.

Divide dough into 6 parts (about 1/4 cup each) and drop by spoonful onto cookie sheet, about 3 inches apart.

Bake 10 minutes. Reduce oven temperature to 325° and continue baking for 20-25 minutes or until deep golden brown. Remove from oven and allow to cool 2-3 minutes. Transfer puffs to a wire rack.

Allow puffs to cool 2-3 more minutes or until they are cool enough to handle.

Cut a small portion off the top of each puff and set aside the base.

Gently use a spoon to “pull” the soft dough from inside each lid and base, careful not to tear the puff. Discard the soft dough. Cool completely.

When cool, the puffs can be stored in an air-tight container in the refrigerator for one day. The puffs will not spoil after that but will not maintain their texture.

In a medium saucepan, whisk together sugar, cocoa, and cornstarch. Combine milk and instant coffee and stir into sugar mixture. Bring mixture slowly to a boil over medium-low heat, whisking constantly. Boil for 1 minute. Remove from heat.

Gradually stir a small amount of hot mixture into beaten egg yolk, blending well. Whisk the egg mixture back into saucepan and return to heat. Continue whisking until mixture boils and immediately remove from heat. Stir in butter and vanilla. Pour into heat-proof bowl and allow to cool 10 minutes.

Press a sheet of plastic wrap onto surface of pudding and refrigerate for at least 3 hours.

When ready to serve, scoop pudding into cream puff base, place lid on top and sprinkle with powdered sugar.