Pre-heat an oven to 180°C. In a tray, place the squash, onions, sage and half the rosemary and dress with olive oil and balsamic vinegar, season. Roast in the oven for 40 minutes, shaking occasionally. In a bowl, dress the garlic cloves with olive oil, salt and pepper and place with the squash. Roast for a further 20 minutes until the squash is roasted and the garlic is sweet and roasted in it's skin.
Sprinkle the pine nuts, remaining rosemary and break the cheese over.
For the sabayon, whisk the yolks and sugar until smooth then add the cinnamon. Over a pan of boiling water, whisk until it doubles in volume. Allow to cool a bit, then fold in whipped cream.
Warm the spinach through and dress on a warm plate. Carefully spoon the squash mix on top. Heap over spoonfuls of the Sabayon. Use a blow torch to help caramelise the dish, or place it under a grill for a few minutes. Drizzle with extra virgin olive oil.