Preheat oven to 180°C. Place paper liners in 8 muffin cups. Place muffin cups on baking tray. (Paper or cardboard moulds are good too. This recipe isn't fussy about what it's baked in.)
TO MAKE CUPCAKES, whisk eggs, glucose and castor sugar till ribbon stage, i.e. mixture is pale and, when whisk is lifted, drips back into bowl and stays visible.
100 g eggs, 6 g glucose, 40 g castor sugar
Sift half of cake flour into egg mixture, moving sieve around bowl so that flour isn't clumped in one area. Gently stir just top part of eggs with whisk, till you see only a bit of flour. Sift remaining half of flour as before. Add salt. Repeat gentle mixing, this time till you don't see any flour.
40 g cake flour, 1/16 tsp salt
Stir milk, oil and vanilla extract till well mixed. Gently drizzle mixture around bowl. Mix with whisk till you don't see any oil, again stirring just top part of batter. Using spatula, scrape down thoroughly and fold till just evenly mixed. Divide batter equally between muffin cups, i.e. 27 g each.
10 g full-fat milk, 30 g corn oil – add to milk, ½ tsp vanilla extract – add to milk and corn oil
Bake 10 minutes on middle shelf till batter is risen. Transfer to upper-middle shelf. Continue baking till golden brown and slightly springy when pressed, another 5 minutes or so.
Remove cakes to wire rack. Wait 5 minutes. Unmould. Serve whilst warm and top is slightly crusty. Alternatively, leave till cool and serve topped with buttercream.
TO MAKE BUTTERCREAM, cook sugar and egg white over low heat, whisking constantly and checking from time to time if sugar is melted by rubbing drop of mixture between fingers.
50 g sugar, 30 g egg white
When sugar is just melted, whisk on high speed mixture till thick, glossy and cold. Add half of butter. Whisk on high speed till well combined. Add remaining butter. Whisk on high speed till mixture is stiff.
85 g unsalted butter
Pipe or spread on cupcakes as desired. Recipe makes enough for frosting 16 cupcakes, or 8 if you're a pig.