1. Line a 20cm springform tin with non stick baking paper. Preheat the oven to 180°C.
2. Cream the butter, sugar and vanilla in a bowl until pale and fluffy.
3. Beat in the eggs, 1 at a time, adding a spoonful of the flour with the second egg. Sift the remaining flour, a pinch of salt, bicarbonate of soda and the nutmeg together.
4. Fold half the flour into the creamed mixture. Fold in the soured cream, zest and almonds, then the remaining flour.
5. Peel, core and slice the pears. Toss with lemon juice to prevent discolouration. Spread half of the cake mixture over the base of the tin, cover with the pears, then the remaining cake mixture. Bake for 40 minutes.
6. Meanwhile, make the almond topping. Melt the butter in a pan and stir in the sugar and cream, then stir in the almonds.
7. Remove the cake from the oven and pour the almond mixture evenly over the top. Bake for a further 20-25 minutes, or until the topping is toffee-coloured and a skewer comes out clean from the centre of the cake. Remove and serve warm or cold.