Cheese-Filled Rhubarb Coffeecake

This mammoth coffeecake, designed to feed a crowd, elicited lots of praise from our crew here at the office, both for its appearance and its taste. Featuring a cheese Danish-like filling enveloped by a yeasted sweet dough crust, topped with rhubarb/pineapple sauce, and gilded with streusel topping, this cake will easily feed 20 people, and it's equally good for breakfast or as a dessert.
Fruit Filling
1 pound fresh rhubarb (approximately 4 cups chopped)
2 tablespoons sugar
1 can (16 ounces) crushed pineapple in juice
1/2 cup sugar
2 teaspoons vanilla

Crust
5 cups (approximately) King Arthur Unbleached All-Purpose Flour
1/2 cup sugar
1 teaspoon (really!) active dry yeast
1/4 teaspoon salt
1 cup milk
1 stick unsalted butter
4 eggs

Cheese Filling
24 ounces (three 8-ounce packages) cream cheese, room temperature
1/2 cup sugar
3 eggs
1 1/2 tablespoons vanilla

Topping
1 cup King Arthur Unbleached All-Purpose Flour
1/2 cup sugar
1 teaspoon cinnamon
1 stick unsalted butter, chilled, cut into chunks
For fruit filling: Clean the rhubarb and chop it into 1/2-inch pieces. Put in a bowl, sprinkle with 2 tablespoons sugar, and let sit several hours or overnight, till the rhubarb releases some of its juice.

Place the undrained rhubarb in a heavy saucepan, add the 1/2 cup sugar and undrained pineapple, and stir to combine. Cook over medium heat, stirring occasionally, until mixture is like thick applesauce. Stir more frequently toward the end of the cooking time, so filling doesn't burn. This will take about 1 hour. Remove from heat and set aside. When cool, stir in vanilla.

For crust: Heat milk and butter, cut in pieces, in a saucepan over medium heat until mixture reaches about 120°F. Combine 1 cup flour, sugar, yeast and salt in a bowl. Pour milk mixture over dry ingredients, stirring to mix well. Beat in eggs one at a time, then add an additional 3 1/2 cups of flour, mixing to combine. Turn the dough onto a well-floured work surface and knead, adding additional flour as necessary, until dough is smooth and elastic. Place dough in a greased bowl, turning to coat all surfaces, cover bowl, and set in a warm spot to rise until dough is doubled in bulk, about 2 hours.

For cheese filling: Beat the cream cheese, eggs, sugar and vanilla until smooth. Set aside.

For topping: Mix the flour, sugar and cinnamon in a medium-sized mixing bowl. Cut in the butter, as you would for pie crust, working it in until mixture is coarse and crumbly.

To assemble: Butter a 12 x 18 x 1-inch rimmed baking sheet (a half-sheet pan). Punch dough down, and divide into two pieces. On a large, well-floured surface, roll one piece of dough into a 12 x 18-inch rectangle. Fit into pan. Spread cheese filling on dough in pan to within 1/2-inch of edge, then top evenly with fruit filling. Roll the second piece of dough into a 14 x 18-inch rectangle, to stretch over filling. Place it on top of the filling, then seal edges, trimming off any extra dough. Brush top crust with melted butter, and sprinkle with topping. Let rise in a warm place for about 15 minutes, while you preheat the oven to 350°F.

Bake cake for 45 minutes, or until cake is golden brown and firm to the touch. Serve warm or at room temperature. Makes 24 3 x 3-inch pieces.