Mix the flour, semolina, sugar and baking powder.
Dissolve the baking soda in the yoghurt and while stirring nonstop with a whisk, add the dry ingredients.
Mix together the walnuts, pumpkin, vanilla and cinnamon.
Oil the tray and pour 1/2 the main mixture into it, pour the pumpkin mixture on top and then the remaining mixture.
Bake in a moderate oven until ready.