A moist, comforting sponge pudding steamed or baked to perfection, drenched in warm pouring syrup or rich toffee sauce.
Beat sugar and eggs together in a bowl for 5 minutes until pale, thick, and creamy; beat in the apricot jam.
Melt butter with the vinegar and mix into the milk.
Sift flour, bicarbonate of soda, and salt together; fold into the egg mixture alternately with the milk mixture to form a smooth batter.
Pour batter into a buttered ovenproof baking dish and bake at 180°C for 30-35 minutes until well risen, spongy, and deep golden brown.
While the pudding bakes, combine double cream, butter, sugar, boiling water, and vanilla extract in a saucepan; simmer over medium heat for 3 minutes until butter and sugar melt.
As soon as the pudding comes out of the oven, prick holes all over the hot surface with a skewer and slowly pour the hot cream sauce evenly over the top; let stand 15 minutes to soak completely.
Serve warm with generous ladles of homemade vanilla custard or vanilla bean ice cream.