This recipe originally accompanied Poppy-Seed Angel Food Cakes with Lemon Syrup .
Halve vanilla bean lengthwise and scrape seeds into a small saucepan. Finely grate enough zest from lemon to measure 1/2 teaspoon. Cut remaining peel from lemon, removing all white pith. Cut enough sections free from membranes to measure 1/4 cup and cut into 1/4-inch pieces. Add lemon pieces to pan with sugar, water, and grated zest. Simmer mixture, stirring, until sugar is dissolved and stir in lemon juice. Cool syrup to room temperature and serve with cakes.