Preheat oven to 375℉ / 190℃.

Prepare choux pastry dough according to this choux pastry recipe. When the choux pastry dough is ready, place it in a pastry bag that has a large round tip (or simply cut the tip off of the pastry bag).

Prepare baking trays by lining it with parchment paper or silpat.

Pipe 1 ½ inch round choux pastry mounds on to the baking sheet, with at least 1 inch space between each. (When piping choux pastry, keep the tip at a 90 degree angle and slightly embedded just under the surface of the piped choux pastry. This is to ensure the piped shape is as smooth as possible).

Either use a water dipped scissor to "cut" the dough, or gently twist the piping tip away from the pastry once you've piped the dough. Then gently flatten the pointy tip with a damp finger.

Mist the surface of the baking tray and pastries with water (either using a mister or lightly sprinkle water with your hands - this is an optional step).

Transfer the piped choux pastry to the preheated oven. Bake in preheated oven for 30 - 40 minutes in the center of the oven, or until the choux pastry shells puff up and are golden brown on top. Do not open the oven door at least until you have reached the 25 minute mark.

During the last 5 minutes of baking, use a toothpick to quickly pierce each pastry. Bake for the final 5 minutes to allow the pastry to dry out.

Remove from the oven, and prick each shell with a toothpick again and let them cool down completely.

Follow instructions in this vanilla pastry cream recipe to make the pastry cream. I recommend adding gelatin for extra stability. You can also make diplomat cream for a lighter filling option.

When the prepared choux pastry has been chilled, place the pastry cream in a piping bag with a bismarck filling tip, or round tip (about ½ cm). Keep it chilled until needed.

Make the sauce just before you're ready to dip the pastries in the sauce. Place all the ingredients, except for the butter and bourbon, in a saucepan or microwave-safe bowl.

Heat over medium low heat (or over a double boiler). Stir and almost melt the chocolate - about 90%. Then remove the saucepan from the heat and stir to dissolve all the chocolate with the residual heat. This can be done in the microwave as well.

While the sauce is warm, add the softened butter and bourbon and whisk to mix completely. Use a stick blender to make sure that the sauce is not grainy and is smooth and shiny.

Use immediately.

Cut an ‘x’ on the bottom of the choux pastry (see photos in the post). Pipe in the pastry cream (with a bismarck tip), until the pastry cases are almost full. You can also use a small french star tip (1 cm) and cut a hole on the bottom using this tip as well.

Dip them in the chocolate sauce, and shake off the excess. Place the pastries on a baking tray and allow the chocolate to set a little.

Place the profiteroles on a plate and keep in the fridge (covered) until ready to serve. The pastries are best filled as close to serving time as possible, to prevent them from getting too soggy.

You can also choose to pour the warm chocolate sauce over the profiteroles just before serving.