Iced Spiced Hermits

Name: Iced Spiced Hermits
Cuisine: British, European
Ingredients: 2 cups (250 g) all-purpose flour; 1½ tsp. ground cinnamon; 1½ tsp. ground ginger; 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt; ¾ tsp. baking soda; ½ tsp. freshly grated nutmeg; ¼ tsp. baking powder; ¼ tsp. freshly ground black pepper; 1 cup (packed; 200 g) light brown sugar; ½ cup (1 stick) unsalted butter, room temperature; 1 large egg; ¼ cup mild-flavored (light) molasses; ½ cup (80 g) golden raisins; 1 cup (110 g) powdered sugar, sifted; 2 Tbsp. (or more) milk, fresh lemon juice, or rum