Place the butternut squash into a small saucepan. Cover with water and bring to the boil. Simmer until cooked through. Strain off most of the water, reserving it in case the puree is too thick. Mash or blend the squash to form a smooth purée, adding cooking liquor as needed. Season with a little salt.
Place the squash purée in a bowl and beat in the egg yolks. Add the cumin and the self raising flour. Stir until well combined.
Wilt down the spinach leaves in a saucepan with a scant amount of water. Set aside and keep warm.
Heat a large non stick frying pan over medium high heat.
Whip the egg whites to form stiff peaks. Mix in half of the egg whites into the squash batter. Fold the remaining egg white into the batter to form a light batter. Season with salt and pepper to taste.
Add a little butter or oil to the heated pan and swirl around. Ladle in some of the batter to form a large pancake. Cook until it is nicely coloured on the underside. Top with a quarter of the spinach and pieces of Taleggio. Roll up the pancake. Set aside and keep warm. Repeat this process with the remaining batter mix to make 4 large pancakes.
Allow 2 filled pancakes each and serve on warmed plates