Combine the flour, salt and sugar in the bowl of a food processor or a large bowl. Add the butter and pulse until the mixture resembles cornmeal; by hand, blend with a pastry blender. Slowly pulse or stir in the water, a little at a time, just until the dough comes together. Gather the dough into a ball, wrap in plastic and chill for at least 1 hour.
Place the dates in a food processor or blender and pulse 2 or 3 times. Add the remaining ingredients and puree until smooth, stopping to scrape down the sides from time to time.
Fill a medium bowl with cold water and stir in the lemon juice. Cut the apples in half and remove the core. Peel the apples and drop them into the bowl of cold water (this acidulated water will keep them from turning brown). Remove the dough from the refrigerator and unwrap. Divide the chilled dough in half. On a lightly floured surface, roll out half of the dough into a 15" square about 1/8" thick. Trim the edges to square it off, then cut into quarters. Slice in 1-1/2" from each corner toward the center. Repeat with the remaining dough. Preheat the oven to 375 °F. Very lightly spray a baking sheet with vegetable oil. Gently whisk the egg yolks and cream together to create an egg wash; do not beat. In a small bowl, combine the sugar and cinnamon. Drain the apple halves and pat dry. Place the apple half, core side up, on each square. Fill the centers with 1-1/2 T of date butter and fold the corners up around each apple, pinwheel-style, pressing to seal. From the dough trimmings cut 8 triangles and pinch each at one end to form a leaf shape. Brush with egg wash and place one on top of each dumpling. Brush the dumplings with egg wash and sprinkle with the cinnamon sugar. Place the dumplings on the baking sheet and bake 20 to 25 minutes until the pastry is golden and the apples are soft when pierced with a knife. Remove from oven and put in a warm place.
In a small saucepan, whisk together the brown sugar, cornstarch and water. Add the cinnamon sticks and bring the mixture to a boil over medium heat. Reduce to medium-low heat and simmer 5 minutes or until the mixture thickens to the consistency of syrup. Remove from heat and stir in the butter and rum. Keep warm.
Place one dumpling to one side in each of four large soup bowls. Ladle sauce over the tops of the dumplings until it covers the bottoms of the bowls. Dust with confectioners sugar. Serve with a large scoop of vanilla ice cream beside each dumpling. Garnish with cinnamon sticks. 8 servings.