How to Make It
In a saucepan, toast the coriander seeds over moderate heat until fragrant, 1 minute. Add the vinegar, sugar, bay leaves, crushed red pepper and 2 tablespoons of salt. Bring just to a boil, stirring to dissolve the sugar and salt. Remove the brine from the heat and add the ramps and garlic. Let stand at room temperature for 2 hours. Drain the ramps, reserving 3 tablespoons of the brine.
In a bowl, mix the ricotta with the 3 tablespoons of oil. Season with salt and pepper.
In a skillet, cook the pancetta over moderate heat, stirring, until browned and just crisp, 8 to 10 minutes. Remove from the heat and add the reserved 3 tablespoons of brine, scraping up any browned bits in the pan.
Preheat the broiler and set a rack 8 inches from the heat. Brush the bread with oil and arrange in a single layer on a large rimmed baking sheet. Broil until golden, 1 minute per side. Spread half of each crostini with the ricotta and top with the pickled ramps, pancetta and any pan juices, then serve.
The pickled ramps can be refrigerated for up to 1 week.