Follow these simple steps to create your Nectarine Shortcake:

1. Preheat the Oven: Start by preheating your oven to 400°F (200°C). Grease a round cake pan or line it with parchment paper.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt until combined.
3. Add Butter: Add the cold, cubed butter to the dry ingredients. Use a pastry cutter or your fingers to mix until the mixture resembles coarse crumbs.
4. Combine Wet Ingredients: In a separate bowl, mix together the milk and vanilla extract.
5. Form Dough: Pour the wet mixture into the dry ingredients. Stir gently until just combined; do not overmix.
6. Shape the Shortcake: Turn the dough onto a lightly floured surface. Pat it into a round shape about 1-inch thick. Transfer to the prepared pan.
7. Bake: Bake in the preheated oven for 25-30 minutes or until golden brown on top. A toothpick inserted in the center should come out clean.
8. Cool: Remove from the oven and let cool in the pan for about 15 minutes. Then, transfer to a wire rack to cool completely.
9. Prepare the Nectarines: In a bowl, toss the sliced nectarines with brown sugar. Let them sit for about 10 minutes to release their juices.
10. Whip the Cream: In a mixing bowl, whip the heavy cream with powdered sugar and vanilla extract until soft peaks form.
11. Assemble the Shortcake: Slice the cooled shortcake in half horizontally. Place the bottom half on a serving platter and top with half of the nectarines and a generous dollop of whipped cream. Place the top half of the shortcake on top and repeat with the remaining nectarines and whipped cream.