01 -
In a bowl, whisk together cornstarch, sugar, and salt. Add egg yolks and beat until lighter in color. In a pot, heat milk with vanilla extract and vanilla bean seeds until bubbles form at the edges (don't boil). Slowly add warm milk to the egg mixture, then return everything to the pot. Cook over medium-low heat, whisking constantly until thickened. Remove from heat, add butter, and mix until incorporated. Transfer to a bowl, cover and refrigerate until chilled.
02 -
In a large bowl, combine warm milk, yeast, sugar, salt, and egg, whisking until smooth. Add softened butter and flour, then knead with a stand mixer's hook attachment or by hand for 2-3 minutes. Transfer to an oiled bowl, cover, and let rise in a warm place for 1.5-2 hours.
03 -
Roll out the risen dough on a floured surface to about 1/2 inch thickness or less. Use a heart-shaped cookie cutter to cut out donuts. Gather scraps, reroll, and cut until all dough is used. Place on an oiled baking sheet, cover, and let rest for 30 minutes.
04 -
Heat vegetable oil to 325-350°F in a deep pot. Carefully add donuts in small batches, frying until golden brown on each side. Transfer to paper towels or a wire rack to drain excess oil.
05 -
Fill a piping bag fitted with a small tip with the chilled custard. Make a deep hole in one side of each donut and pipe the custard inside until filled.
06 -
In a small pan over medium heat, combine sugar and water. Bring to a boil without stirring (to prevent crystallization) until the sugar dissolves and turns golden brown. Reduce heat to low until it reaches a deeper amber color, then remove from heat.
07 -
Working quickly before the caramel hardens, dip one side of each filled donut into the hot caramel, allowing excess to drip off. Place on a wire rack to set. Serve fresh for the best texture contrast between the crunchy caramel top and soft donut.