Making the Pastry
- Preheat the oven to 425°F (220°C). Line a cookie sheet with parchment paper to prevent the cream puffs from sticking during baking.
- Sift the dry ingredients. In a bowl, sift together the flour, salt, and baking soda. Set this aside.
- Melt the butter in water. In a heavy saucepan, combine the water and butter. Place the pan over medium heat and bring to a simmer until the butter has completely melted.
- Combine flour with butter mixture. Once the butter has melted and the water is simmering, remove the saucepan from the heat and add the sifted flour mixture all at once. Stir vigorously with a wooden spoon until the mixture forms a smooth dough and starts to come away from the sides of the pan.
- Beat in the eggs. Return the pan to medium-high heat and, one egg at a time, add the eggs to the dough, beating after each addition until the egg is fully incorporated. The dough should be smooth and slightly glossy.
- Shape the dough. Transfer the dough to a pastry bag fitted with a ½-inch tip. On the prepared baking sheet, pipe 3-inch puffs, spaced about ½ inch apart. You should aim for 12 large or 24 small cream puffs, depending on your preference.
- Bake the cream puffs. Place the baking sheet in the preheated oven and bake for about 20 minutes, or until the cream puffs are golden brown and puffed up. Once they’re done, carefully slit the side of each puff with a knife to allow the steam to escape. This step prevents the inside from becoming soggy.
- Cool the pastries. Transfer the baked puffs to a cooling rack and let them cool completely before filling them with the custard.
Preparing the Custard
- Combine dry ingredients. In a saucepan over moderate heat, combine the sugar, flour, and salt. Stir well to ensure the dry ingredients are evenly distributed.
- Add the milk. Gradually add the whole milk to the dry ingredients, stirring constantly to avoid lumps. Cook the mixture, stirring frequently, until it becomes thick and bubbly.
- Temper the egg yolks. In a small bowl, lightly beat the egg yolks. Slowly pour a bit of the hot milk mixture into the yolks while whisking constantly. This process, known as tempering, prevents the eggs from scrambling when added to the hot liquid.
- Combine and cook. Pour the egg mixture back into the saucepan with the rest of the milk mixture. Stir constantly and bring the custard to a gentle boil. Continue to cook for another 2 minutes, or until the custard is thick and smooth.
- Finish the custard. Remove the custard from the heat and stir in the butter, vanilla extract, and rum. The butter will melt into the custard, making it richer and creamier.
- Cool the custard. Transfer the custard to a shallow bowl and place plastic wrap directly on the surface to prevent a skin from forming. Let the custard cool to room temperature, then refrigerate it until fully chilled.
Assembling the Cream Puffs
- Pipe the custard. Once the custard has cooled completely, transfer it to a pastry bag. Cut a small opening at the end of the bag and pipe the custard into the center of each cream puff, filling them generously.
- Decorate. Top each cream puff with a maraschino cherry and dust lightly with powdered sugar. The cherry adds a pop of color and a touch of sweetness, making the cream puffs look even more inviting.