Florian's Sandwich Rolls

In a 2-cup glass measuring cup, dissolve yeast in mineral water; set aside. In the bowl of an electric mixer fitted with the dough-hook attachment, combine bread flour and 1 1/4 cups cake flour. With the mixer on low, gradually add the yeast mixture to the flour, and continue to mix until combined. Turn off the mixer and let rest, covered, for 10 minutes.

In a medium bowl, whisk to combine the remaining 4 cups cake flour and 1 tablespoon salt. In a medium bowl, whisk to combine oil, simple syrup, and egg yolks. With the mixer on low, gradually add milk to the flour mixture, and beat until combined. Gradually pour in three-quarters of the oil mixture, and beat until the dough no longer sticks to the side of the bowl. Add the remaining one-quarter oil mixture, and continue to beat on medium-low for 3 minutes.

Remove dough to a lightly floured baking sheet. Cover with plastic wrap, and let rest for 10 minutes.

Preheat oven to 450 degrees. Line baking sheets with parchment paper. Divide dough into 23 three-ounce pieces. On a lightly floured work surface, roll each piece into a ball and place on baking sheets 4 inches apart. Let rise in a warm place until doubled in size, about 20 minutes. In a small bowl, whisk together egg and the remaining pinch salt. Brush dough with egg mixture, and bake until golden brown, 18 to 20 minutes. Remove from oven and cool on a wire rack. These are best eaten the same day.