Step 1

Place citrus zest in a medium saucepan and pour in cold water to cover. Bring to a boil; drain. Repeat process 2 more times.

Step 2

Combine sugar and 2 cups water in same saucepan; bring to a boil, stirring to dissolve sugar. Add citrus zest and bring just to a simmer. Reduce heat to low and simmer very gently until peels are translucent, 30–45 minutes. Remove from heat and let citrus zest cool in syrup.

Step 3

Drain citrus zest and finely chop. Spread out on a rimmed baking sheet; let sit until dry.

Step 4

Preheat oven to 350°. Toast ginger, cardamom, cinnamon, and cloves in a small skillet over medium heat, stirring with a wooden spoon, until fragrant, about 2 minutes. Remove from heat.

Step 5

Sift toasted spices, flour, baking soda, salt, and white pepper into a medium bowl or onto a sheet of wax paper.

Step 6

Using an electric mixer on medium-high speed, beat butter and both sugars in a large bowl until light and fluffy, about 4 minutes. Add eggs one at a time, beating well after each addition and scraping down sides of bowl as needed. Beat in molasses. Gradually add dry ingredient in 2 batches, beating on low speed to incorporate after each addition. Stir in 1 cup candied citrus peel.

Step 7

Drop dough by rounded tablespoons between 2 parchment-lined baking sheets, spacing 2" apart. Bake cookies until tops feel firm when lightly touched, 10–12 minutes. Let cool on baking sheets about 2 minutes, then transfer to a wire rack and let cool completely.