For dough: In the bowl of a stand mixer fitted with the paddle attachment, whisk together 3 cups flour, granulated sugar, yeast, and salt by hand.
In a small saucepan, heat 3⁄4 cup water, butter, milk, and vanilla over medium heat until butter is melted and an instant-read thermometer registers 120° to 130°. With mixer on low speed, slowly add warm milk mixture to flour mixture, beating until combined, about 30 seconds. Add eggs, beating until combined. Add remaining 3 cups flour, and beat at low speed until a shaggy dough forms.
Switch to the dough hook attachment. Beat at low speed until dough is smooth and elastic, 8 to 9 minutes. Turn out onto a lightly floured surface, and shape into a smooth round.
Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Loosely cover and let rise in a warm, draft-free place (75°) until doubled in size, 30 to 45 minutes.
Spray a 13x9-inch baking pan with baking spray with flour.
For topping: In a medium saucepan, melt butter over medium heat. Stir in brown sugar, corn syrup, cream, and salt; bring to a boil over medium heat. Pour into prepared pan, and sprinkle pecans and pineapple tidbits on top in a single layer. Let cool completely.
Lightly punch down dough. Turn out dough onto a lightly floured surface, and roll into an 18x14-inch rectangle.
For filling: In a small bowl, whisk together preserves, mashed banana, and cinnamon. Whisk in flour. Stir in diced banana. Spread onto dough, leaving a 1-inch border on one long side. Starting with long side opposite border, roll up dough into a log, and place seam side down. Trim ends. Using a serrated knife, cut into 12 (1 1⁄2-inch-thick) slices. Place in prepared pan on top of pecans and pineapple. Cover with plastic wrap, and let rise in a warm, draft-free place (75°) until puffed and slices are touching, 30 to 45 minutes.
Preheat oven to 350°.
Bake until a wooden pick inserted in center comes out clean and an instant-read thermometer inserted in center registers 190°, 35 to 40 minutes. Let cool in pan for 5 minutes. Invert buns onto a serving platter. Spoon any pecan caramel left in pan on top of buns. Serve warm.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/hummingbird-sticky-buns/