Soft, fluffy, buttery, yeast dough swirled with mixed spices, candied lemon peel, and dried currants can't even begin to describe these deliciously sticky, caramelized pastries that have been part of Britain's culinary heritage for over 300 years. These Chelsea Buns capture all the warmth and charm of traditional English baking.
Place all of the ingredients for the dough in the bowl of a stand mixer with the dough hook attached. Knead the dough on medium speed for 5-7 minutes until a soft, smooth dough forms (alternatively knead by hand on a floured surface for 10 minutes). If it's too sticky, add a little more flour or if it's too dry add a little more milk. Remove the dough, lightly spray the bowl with oil, form the dough into a ball, place it back in the bowl and cover with plastic wrap. Let the dough rest in a warm place until it has nearly doubled in size, about an hour or longer. Preheat oven to 375°F/190°C. Grease a 8x8 or 9x9 inch square baking pan.
Roll the dough out onto a silicone mat or very lightly floured surface in a 14×8 inch (36x20cm) rectangle. Spread the butter evenly over the surface of the dough, leaving a border at the side furthest away from you. Evenly sprinkle the brown sugar over the buttered area followed by the mixed spice and cinnamon and then the dried currants and candied lemon peel. Pick up the side of the dough closest to you and roll the dough into a log. Trim off a little dough from each end to tidy it and then cut the roll into 9 equal slices. Place the rolls cut side up in the greased square baking pan and cover with plastic wrap. Let rise in a warm place for about 30 minutes, or until puffy and nearly doubled in size. Bake on the middle shelf for roughly 18-25 minutes or until golden brown. For precise doneness, an instant read thermometer will register between 195–200°F (91–93°C) when they're done.
While the Chelsea buns are baking (towards the end) make the glaze: Combine the sugar and water in a small saucepan and stir over medium heat until the sugar is melted and the syrup just begins to bubble then remove from the heat. This will produce a clear, sticky glaze. If you prefer a firmer glaze let the syrup boil for a minute or two longer. Take the Chelsea buns out of the oven and, while they're still hot, brush the tops with the sugar glaze. Let cool until just warm and then turn them out onto a serving tray and serve.