Roast the Pumpkin:
Peel and cube fresh pumpkin. Toss with a bit of olive oil and cinnamon, then roast at 400°F (200°C) for 25–30 minutes until soft. Mash into a purée and let cool.
Prepare the Batter:
Mix semolina, almond flour, baking powder, salt, cinnamon, and cardamom in a bowl.
In another bowl, mix pumpkin purée, yogurt, melted butter, sugar, and vanilla.
Combine wet and dry ingredients. The batter should be thick.
Bake:
Spread batter into a greased 8x8 inch pan or round cake pan. Smooth the top.
Optional: lightly score diamond shapes or place a whole almond or pistachio in each square.
Bake at 350°F (175°C) for 35–40 minutes until golden brown and springy.
Make the Syrup:
While baking, simmer sugar, water, and zest for 5–7 minutes until slightly thickened.
Remove from heat and stir in orange blossom water.
Soak & Serve:
When the basbousa comes out of the oven, immediately pour warm syrup evenly over it. Let it soak fully (at least 15 minutes). Garnish as desired and serve slightly warm.