Cobalt Crackle Cookies

Procedure

1. Mix the dry. Whisk the all-purpose flour, baking powder, baking soda and ½ teaspoon fine salt in a bowl.
2. Beat until fluffy. Beat the butter and 1 cup granulated sugar with a mixer on medium-high until pale and fluffy, 2 to 3 minutes.⏱ 3:00
3. Turn it cobalt. Beat in the egg, lemon juice, lemon zest, vanilla extract, royal blue gel coloring and the toothpick tip of violet gel coloring until the dough is evenly cobalt. Aim a shade deeper than you want; the snow coat softens it.
4. Bring it together. Add the dry mixture and mix on low just until no streaks of flour remain.
5. Chill. Cover and refrigerate the dough until firm, 1 hour. Cold dough spreads less and cracks sharper; the cold is back on the team. For the last 15 minutes, heat the oven to 350°F (175°C) and line two baking sheets with parchment.⏱ 1:00:00⏱ 15:00
6. Double roll. Put the ½ cup granulated sugar and the powdered sugar in separate bowls. Scoop 1½-tablespoon (about 26 g) balls of dough, roll each in the granulated sugar, then in the powdered sugar until thickly coated, and space them 2 inches (5 cm) apart on the sheets.
7. Bake. Bake one sheet at a time until the edges are set and the tops are puffed and cracked but still soft in the centers, 10 to 12 minutes. Pull them before the edges brown; browning pushes the blue toward green.⏱ 12:00
8. Cool. Cool on the sheet for 5 minutes, then move the cookies to a rack.⏱ 5:00