I made these for an Icelandic holiday tomorrow called Bolludagur, for details see Candy Hearts and Paper Flowers tomorrow. This recipe makes a choux pastry, pâte à choux, and is translated from metric measurements, I hope it works out for you. This site has pretty good pictures of the process and what it looks like at each stage. This pastry gets it's height from the steam created by the moisture of the batter, if you open the door you will lose that steam and your puffs will fall. This pastry would be the perfect example of why ovens have a light inside and a window in the door.
1 1/3 cup water
1 stick butter
1 1/4 cup flour
1 cup whipping cream
2 Tbsp powdered sugar
1/2 cup Semisweet Chocolate, chopped
3 Tbsp cream
Preheat oven to 400 degrees
Heat water and butter in small pot until it just comes to a boil
Add flour to the pot all at once and stir until incorporated, continue stirring for 1 minute or until film starts to form on the bottom of the pot (about 1-2 minutes)
Add eggs 1 at a time and combine completely before adding next egg.
This will form a very soft dough that you drop by tablespoonful onto a parchment sheet lined cookie sheet
Cook for 23-26 minutes at 400 degrees until very light golden brown
Do not open the oven to check the puffs or they will fall, use the window to get an idea of color.
After the pastry comes out of the oven let them cool completely before assembling.
Prepare filling by whipping cream until soft peaks form, sift in powdered sugar and whip additional 5 seconds
Place chocolate in microwave for 15 seconds
Add cream, microwave for additional 15 seconds
Mix well, microwave in additional 15 second intervals, if needed until you can stir it until smooth.
Top with dollop of whip cream
Dip top in chocolate and nestle on top of whip cream