Peel and halve the pears and cut out the core. Carve the pear halves. Fill a bowl with water and add the lemon juice. Put the pears in it. For the dough, mix the fat, 200 g sugar, 1 sachet vanilla sugar, salt and grated lemon peel until creamy.
Stir in 4 eggs alternating with 4 tablespoons of spelt flour one after the other. Mix the remaining flour and baking powder and stir in briefly together with the cream. Pour the dough onto a greased, floured fat pan of the oven and smooth it down.
Place the pear halves on the dough with the round, incised side facing upwards. Mix sour cream, 4 eggs, 100 g sugar and 1 packet of vanilla sugar. Pour the sour cream evenly over the pears.
Bake in the preheated oven, mid-height (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 45 minutes. Heat apricot jam and 1-2 tablespoons of water in a small pot and pass through a sieve.
Spread the pears with the jam after about 30 minutes and sprinkle with brown sugar. Finish baking the cake, covering the last 5 minutes if necessary. Let the pear-spelt cake cool down in the fat pan on a cake rack.
Cut the cake into pieces and decorate with lemon balm. This is accompanied by sour cream.