- Add the chocolate to a heatproof bowl and set aside while you heat the milk.
- Pour the milk into a small saucepan. Add the sugar and salt. Cook over medium heat, whisking a few times to a low boil.
- Immediately remove the saucepan from the heat. Pour the hot milk over the chopped chocolate all at once. Rotate the bowl so the chocolate is completely submerged. Cover the bowl with a plate and let stand undisturbed for 4 minutes.
- Add the vanilla and olive oil (if using) and whisk from the center out only until smooth and glossy.
- Keep the bowl of ganache at room temperature while you test the final consistency. Dip a teaspoon into the ganache, set the coated spoon on a small plate, and refrigerate for 10 to 15 minutes. After chilling, the ganache on the spoon should be smooth and firm, but should still taste creamy. It is unlikely, but if the glaze is too firm, add a tablespoon of room temperature milk, and repeat the test. Add a second tablespoon if needed.
- Pass the ganache through a strainer into a bowl. Whisking slowly will speed the process.
- Allow the ganache to thicken at room temperature for 15 to 25 minutes, or until it will coat a spoon thickly with minimal dripping, but remain pourable. Stir a few times from the outside into the center before glazing.
Keeping: The glaze can be refrigerated in a tightly closed container for up to five days and frozen for up to one month. The glaze hardens when it is cold and will need to be reheated. To reheat, spoon the glaze into a heatproof bowl that fits over a saucepan of barely simmering water. When about two-thirds of the glaze is melted, stir gently until it is smooth. Adjust the consistency as needed by stirring warm nondairy milk into the glaze a little at a time.