For the Dough:
For the dough, measure all the ingredients into a bowl and stir with a wooden spoon, or blend in a stand mixer fitted with the hook attachment until evenly combined. If mixing by had, turn the dough out onto a work surface and knead until smooth, about 5 minutes, or if in a mixer, knead for about 3 minutes. Transfer the dough to an oiled bowl, cover with plastic wrap and let rise until doubled in size, 90 minutes to 2 hours.
For the Filling and Assembly:
For the filling, cream the butter with the granulated and brown sugar until evenly combined. Stir in the vanilla, zest and juice. In another bowl, mix the dried currants, glacée cherries and peel together. Set aside.
Turn the risen dough out onto a lightly floured work surface and roll it into a rectangle about 20-x-10 inches. Spread the filling over the entire surface and sprinkle it with the currants, glace cherries and mixed peel. Roll up the dough from the longer side. Cut the dough in half lengthwise and then in half widthwise. Twist 2 pieces of dough together as tightly as possible, then repeat with the other two pieces of dough, then twist both of these pieces together. (don’t worry even some of the fruit falls out – you can sprinkle it overtop once in the pan). Place the twisted dough into a greased 10-x-5-inch loaf pan, cover with plastic wrap and let rise for an hour.
Preheat the oven to 170°C. Uncover the loaf and place it onto a parchment-lined baking tray (to catch any drips of filling or fruit). Bake the Chelsea loaf for about 55 minutes, until a rich brown colour. While hot from the oven, prepare the glaze.
For the Hot Glaze:
Heat the water, sugar and butter together until the sugar dissolves. Spoon this over the hot Chelsea loaf and then let the loaf cool in the tin for 30 minutes before removing to cool completely.
The Chelsea loaf is best enjoyed within a day of baking.