Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.

In a large bowl, whisk together flour, sugar, baking powder, cinnamon, salt, and baking soda. Using your hands or a pastry cutter, cut in cold butter until it resembles course crumbs. Make a well in center.

In a medium bowl, whisk together cold buttermilk and vanilla. Add banana and pineapple. Add buttermilk mixture and chopped pecans to flour mixture, and stir with a spatula until dry ingredients are fully moistened. Knead with your hands once or twice just until dough is smooth and fully hydrated.

Turn out dough, and pat into a 6-inch circle. Cut into 4 equal pieces. Place on prepared pan.

Bake until golden and an instant-read thermometer inserted in center registers 205°F (96°C), 25 to 30 minutes. Let cool on pan for 10 minutes. Remove from pan, and let cool completely on a wire rack. Spread Vanilla Cream Cheese Glaze on top, and garnish with toasted pecans, if desired. Store in an airtight container for up to 3 days.