1.For manjar blanco, stir milk, sugar and vanilla seeds gently over low heat until mixture starts to change colour, then stir continuously until a thick cream-coloured sauce forms (40-50 minutes). Add cream and set aside.
2.Meanwhile, for ponderacion batter, beat ingredients and a pinch of salt gradually until a smooth batter forms.
3.Pour oil into a wide saucepan to 4cm deep and heat to 190C. Holding the rim of a 8cm flower-shaped cutter with tongs, place it in hot oil (be careful, hot oil will spit) until very hot (1 minute), then quickly dip it into the batter up to the top of the mould (it should sizzle when it hits the batter; if it isn’t hot enough, the batter may not stick), then quickly return to oil and fry, holding under the oil with tongs, until golden and crisp (3-5 minutes; be careful, hot oil will spit). Drain on absorbent paper, then shake a little to help detach it from the mould. Repeat with remaining batter, then dust ponderaciones with icing sugar and serve topped with ice-cream and drizzled with manjar blanco to taste.