Preheat the oven to 350°. Spread the almonds on a rimmed baking sheet and toast for about 10 minutes, until fragrant and lightly golden. Let cool completely. In a medium bowl, whisk the flour with the baking powder, cinnamon, ground ginger, cloves, allspice, salt and nutmeg.
In a food processor, pulse the cooled almonds until coarsely chopped. Add the brown sugar and pulse until incorporated. Add the marmalade, candied ginger and molasses and pulse until the mixture is well blended and the nuts are finely chopped. Add the eggs all at once and pulse until just incorporated. Add the dry ingredients and pulse until incorporated and the batter is uniform in color. Scrape the soft batter into a bowl, cover and freeze until very firm, at least 4 hours.
Preheat the oven to 350° and line 2 large baking sheets with parchment paper. Using a 2-tablespoon ice cream scoop, scoop 8 level mounds onto each baking sheet, about 3 inches apart. Freeze the remaining batter between batches. Bake the cookies in the upper and lower thirds of the oven for about 20 minutes, until risen and slightly firm; shift the pans from top to bottom and front to back halfway through. Transfer the sheets to racks and let the cookies and pans cool completely. Repeat with the remaining batter.
In a bowl, whisk the confectioners' sugar with the milk and butter. Spread the cookies with icing and let dry completely before serving or wrapping.