Syrup: In a small saucepan, bring sugar and water to a simmer, stirring until sugar is dissolved. Remove from heat; stir in orange-blossom water. Let cool.
Cake: Preheat oven to 350 degrees. Brush bottom and sides of a standard 9-by-5-inch loaf pan with butter; coat with flour, tapping out excess.
Whisk together flour, salt, baking soda, and cinnamon. In another bowl, beat butter and sugar on medium speed until light and fluffy, 3 to 4 minutes. Add eggs, 1 at a time, then vanilla; beat until just combined. Reduce speed to low. Add flour mixture in 3 batches, alternating with buttermilk in 2 batches, beating until just combined. Fold in walnuts and dates.
Transfer batter to pan. Bake until golden brown and a skewer inserted in center comes out clean, 40 to 45 minutes. Remove from oven; evenly pierce holes at 1-inch intervals in top of cake (all the way to bottom) with skewer, then pour syrup over cake. Let cool in pan.
Serving: Serve slices of cake with whipped cream dusted with cinnamon, and orange segments.
Orange-blossom water, by Mymoune, $16 for 9 oz., kalustyans.com.