The warming flavors of scorched orange peel and crushed cardamom infuse a layer of bitter brightness that builds over time as a mixture of heavy cream, milk, and sugar reduces. Once thick and spreadable, a final showering of burnt orange zest and a pinch of salt ties it all together. The result is less of a candy-like caramel sweetness and instead more of a mellowed-out bittersweetness with toasty, spiced notes. Spread it on toast, waffles, or pancakes; treat it like a custard and pipe it into warm, fluffy doughnuts; or give your alfajores filling an aromatic, bittersweet twist.
- Peel half the orange into long strips, reserve the remaining half for later. Toast orange peel strips over a burner, or with a match, lighter, or torch, to lightly singe edges. Add strips to a 2-quart heavy-bottom saucepot or similar, along with smashed cardamom pods.
- Set the saucepot to a medium heat and toast cardamom along with the singed orange peel until aromatic, about 1 minute.
- Pour in milk and heavy cream (it will sputter when added). Whisk in sugar, salt, and baking soda. Bring up to a simmer, then adjust to low heat and cook for 1½–2 hours, stirring occasionally with a spatula to ensure it does not brown on the bottom. In the last half hour, pay closer attention and adjust heat to maintain a very low bubble. The resulting consistency should be thick and glossy. Strain finished milk jam through a fine mesh sieve into a heatproof vessel to cool and remove solids. The jam should have reduced by more than half and should appear thick, glossy, and light caramel in color.
- When slightly cool, taste and adjust seasoning with additional salt and remaining half orange, very finely grated. Serve with your toast of choice. Store in an airtight container.