Unsalted butter, ¾cup (6oz/185g), at room temperature
Light brown sugar, 1cup (7oz/220g) firmly packed
Light molasses, ⅓cup (3½oz/105g)
Flour, 2cups (10oz/315g)
Baking soda (bicarbonate of soda), 1½teaspoons
Ground ginger, 1teaspoon
Ground cinnamon, 1teaspoon
Ground allspice, ½teaspoon
Prepare the baking sheets
Preheat the oven to 350°F(180°C). Line 2 rimless baking sheets with parchment (baking) paper.
Mix the dough
In a large bowl, using an electric mixer on medium speed, beat the butter and sugar until creamy. Add the egg and molasses and beat until smooth. In another bowl, stir together the flour, baking soda, salt, ginger, cinnamon, and allspice. Add the dry ingredients to the wet ingredients and mix on low speed until blended.
Bake the cookies
Drop level tablespoonfuls of the dough onto the prepared sheets, spacing them 2inches (5cm) apart. Bake until the cookies are browned and firm to the touch, 10–12 minutes. Let the cookies cool on the baking sheets on wire racks for 5 minutes, then transfer the cookies to the wire racks to cool completely.