Preheat the oven to 200C/180C Fan/Gas 6. Line a 32x23cm/13x9in baking tin (about 4cm/1½in deep) with parchment.
Beat the eggs and milk together in a jug.
Mix together all of the dry ingredients, reserving a handful of the pistachios. Stir in the butter and jam. Gradually pour in the egg mixture and mix until smooth.
Pour the mixture into the tin. Roughly crush the remaining pistachios and sprinkle over the surface.
Bake for 35-40 minutes, or until the surface is golden-brown. Check after 25 minutes, if the surface is beginning to burn cover with aluminium foil.
Leave to cool for 10 minutes in the tin before carefully transferring to a wire rack to cool com-pletely. Cut into 12 slices.