Make the caramel sauce first. Place the granulated sugar and two tablespoons of water in a small saucepan over a medium heat. Swirl the pan gently — do not stir — until the sugar dissolves completely. You'll see the liquid turn from cloudy to clear, then bubble and deepen to a rich amber colour, like a warm honey. The smell will shift from sweet to nutty and slightly toasty.

Add the butter and cream. Once the caramel is a deep amber (about 4 minutes), drop in the butter and stir with a wooden spoon. The mixture will hiss and bubble up vigorously — that's normal. Keep stirring until the butter melts completely and the sauce smooths out into a glossy, thick liquid. Remove from heat and stir in the double cream and vanilla extract. The sauce will steam gently and smell intensely buttery and sweet.

Brew the coffee. In your serving mug, dissolve the instant coffee granules in the hot water. Stir until no granules remain — the liquid should be dark and smell robust, with no gritty bits at the bottom.

Steam or heat the milk. Pour the milk into the same small saucepan (rinse it quickly first) and warm over a medium heat until small bubbles appear around the edge and a light steam rises — about 2 minutes. Do not let it boil, or the milk will form a skin. If you have a milk frother, use it now; the milk should look velvety with a layer of fine foam on top.

Layer the drink. Pour the hot milk into the mug over the brewed coffee, holding back the foam with a spoon. The liquid will swirl together into a pale tan colour. Spoon the remaining foam on top — it should sit in a thick, airy cap.

Add the caramel. Drizzle two tablespoons of your homemade caramel sauce over the foam in a zigzag pattern. The warm caramel will sink slowly through the foam, creating that signature layered look. Serve immediately while the caramel is still runny and the coffee is hot.