Beat together the oil, yogurt, vanilla extract, sugar, flour, ground almonds, baking powder and pinch of salt in a large bowl. Add the eggs, one by one, beating well after each addition.
Fold in the chocolate chips and pear and spoon into a deep, round 20 cm (8 inch) nonstick cake tin. Arrange the blanched almonds over the top of the cake, if using.
Place in a preheated oven, 180°C (350°F), Gas Mark 4, for 45–50 minutes or until the cake is risen, golden and firm to the touch.
Leave to cool for 15 minutes in the tin, then remove from the tin and cool completely on a wire rack. Serve in thick wedges with dollops of half-fat crème fraîche, if liked.