To make pine nut brittle, lightly brush a piece of baking paper with oil. Place sugar, 1 tablespoon lemon juice and 3 tablespoons water in a saucepan with a heat–proof handle. Allow sugar to caramelise until light brown. Remove from heat; stir in pine nuts. Spread mixture on baking paper immediately, as much as possible keeping pine nuts separate from each other. Let brittle cool. Break into pieces.
Peel pears, remove seeds and cut into quarters. Cut pear quarters into slices lengthwise. Halve plums; remove stones. Arrange plums and pears on individual plates and drizzle with remaining lemon juice.
To make honey cream: honey, cinnamon and ground cloves together. Whip cream until stiff and fold into quark mixture. Spoon a little honey cream in the centre of each serving. Sprinkle with pine nut brittle. Garnish with lemon balm leaves.