Cover a countertop with two or three sheets of parchment or waxed paper. Pour the cream and sugar into a large, heavy-bottomed pot. Grate the rind of the orange over the pot. Add the corn syrup and pecan pieces. Over medium heat, stir the mixture often until it becomes very thick and a candy thermometer registers 275ºF, about 1 hour.
Remove the pot from the heat. Drop the mixture by the tablespoon, onto the parchment paper, working quickly. Cool completely.
Lift the pralines off the paper with a thin knife. Store in an airtight container between layers of parchment paper at room temperature for up to 2 weeks.
Yield: 3 1/2 dozen