Salted chocolate-glazed yellow cake bars in an isomalt sugar box

Whisk the sugar, salt and room temperature butter until pale and creamy; add the eggs one at a time until both are mixed in.

Add the vanilla paste and baking powder; slowly whisk in the vegetable oil until very smooth; mix in the milk, sour cream and finally the cake flour, stopping as soon as the lumps are gone.

Pour into a baking tray lightly greased with butter around the edges and lined with parchment paper.

Bake at 375F for 25 minutes, checking doneness with a toothpick.

Stir powdered gelatin with a few tablespoons of water in a small ramekin until it thickens.

Heat corn syrup, the thickened gelatin and vanilla bean paste in a small pan until dissolved; add to melted dark chocolate and whisk until smooth, optionally passing through a fine sieve.

Keep the glaze over a hot pot of water so it stays pourable, or cover and refrigerate for later.

Cool the cake a few minutes before removing it from the tray; refrigerating or freezing before cutting stiffens the crumb.

Cut into small bars with a very sharp knife; set on a cake rack over a baking tray.

Spoon, ladle or pour the glaze over until coated on all sides, thinning with a little hot water if it thickens; set in the fridge.

Put isomalt between two silpats on a baking tray and bake at 350F for 15 minutes until completely melted.

Press the melted sugar with a folded cloth to remove large air pockets.

Cut large pieces of the sugar glass, melt each to the length and width of a cake bar, and fuse the sides with a straight-edge spatula and a torch or open stove flame.

Lift a glazed bar with a warm spatula onto a white plate; top with toasted cake crumbles and a pinch of sea salt, and cover with the sugar box.