Preheat your oven to 350°F (175°C). In a saucepan over medium heat, melt the butter. Once melted, add the brown sugar, heavy cream, vanilla extract, and a pinch of salt. Stir continuously until the sugar dissolves and the mixture becomes smooth. Remove from heat and allow it to cool slightly.

Meanwhile, grease a 9-inch round cake pan and arrange the pecan halves in a circular pattern across the bottom. Pour the cooled caramel mixture evenly over the pecans, making sure they are well coated.

In a bowl, whisk together the all-purpose flour, baking powder, and salt. In a separate large mixing bowl, cream the softened butter and granulated sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

Alternate adding the dry ingredients and the milk to the butter mixture, starting and ending with the dry ingredients. Mix just until combined, avoiding overmixing to keep the cake tender.

Pour the prepared batter gently over the pecan topping in the cake pan, smoothing the surface evenly with a spatula. Place the pan in the preheated oven and bake for 35 to 40 minutes, or until a toothpick inserted into the center comes out clean.

Remove the cake from the oven and let it cool in the pan for about 5 minutes. Carefully invert the cake onto a serving plate, revealing the caramelized pecan topping. Serve warm or at room temperature.