- Canola oil
- 2 tablespoons water
- 2 tablespoons fresh lemon juice
- 2 1/2 teaspoons unflavored gelatin
- 2 1/4 cups plain whole-milk yogurt (preferably organic)
- 1 3/4 cups heavy whipping cream, divided
- 3/4 cup sugar
- 6 small ripe plums, thinly sliced
- 1/4 cup sugar
- 1 tablespoon fresh lemon juice
- 1 teaspoon finely grated lemon peel
- Test-kitchen tip: If possible, invert the panna cotta on a flat platter or large plate. A serving piece with sloping sides won't allow the dessert to lie flat and will make it more difficult to slice the panna cotta into wedges.
- Lightly coat inside of 9-inch cake pan with 1 1/2-inch-high sides with canola oil. Combine 2 tablespoons water and lemon juice in small bowl. Sprinkle gelatin over; stir to blend. Let stand until gelatin softens, about 15 minutes. Whisk yogurt and 3/4 cup cream in large bowl. Combine 1 cup cream and sugar in small saucepan; bring to simmer over medium heat, stirring until sugar dissolves. Remove from heat. Add gelatin mixture to hot cream mixture; whisk until gelatin dissolves. Add cream-gelatin mixture to yogurt mixture; whisk to blend. Pour mixture into cake pan. Chill uncovered until cold, then cover and keep refrigerated until panna cotta is set, at least 8 hours or overnight. DO AHEAD: Can be made 2 days ahead. Keep refrigerated.
- Combine plums, sugar, lemon juice, and lemon peel in medium bowl; toss to coat. Let stand at room temperature until juices form, tossing occasionally, about 30 to 45 minutes. DO AHEAD: Can be made 8 hours ahead. Cover and refrigerate.
- Using small knife, cut around panna cotta to loosen edges. Fill large bowl with 1 inch of hot water. Dip bottom of pan into hot water to help loosen. Place dessert platter upside-down atop pan; invert panna cotta onto platter. Carefully lift off pan and allow panna cotta to settle onto platter.
- Cut panna cotta into wedges. Divide among plates. Serve with plum mixture.