Ingredients: 100g butter, 45g powdered sugar (adjust to taste), 1g salt, 2 hard-boiled egg yolks, 140g cake flour, 60g cornstarch.
Prepare all ingredients and portion them into small bowls. Sugar and salt can be combined in one bowl; cake flour and cornstarch can be mixed together. (Eggs should be freshly boiled and soaked in cold water for easy peeling.) Pictured items include cake flour, eggs, sugar and salt, butter, cornstarch, and an electronic scale.
If powdered sugar is unavailable, substitute with other sugars or make your own: blend 50g sugar with 5g cornstarch in a high-speed blender until powdered.
Pour boiling water into a large bowl, then melt the butter by placing its bowl over the hot water until liquid.
Once the butter is fully melted, add sugar and salt to the butter. Stir over hot water until the sugar is completely dissolved (if using powdered sugar, this step can be skipped).
After the sugar and salt are fully dissolved, sift the egg yolks into the mixture and stir until well combined.
Add the cornstarch and cake flour to the mixture, then stir until a uniform dough forms.
Knead the dough into a ball, wrap it in plastic wrap, and refrigerate for 1 hour.
Remove the dough from the refrigerator, knead it briefly, then divide it into small balls and place them on a baking sheet. Press each ball with a finger to create the classic Margaret cookie shape.
Bake at 160°C for 18 minutes. For a first attempt, bake at 150°C for 20 minutes; if undercooked, increase to 160°C for an additional 5–10 minutes. Watch closely—once the cookies begin to turn golden, they are done.
