Preheat your oven to 350°F (175°C). Grease a 9-inch cake pan.
In a saucepan, combine brown sugar, corn syrup, melted butter, and salt. Heat until the sugar dissolves, then pour the mixture into the prepared cake pan.
Sprinkle the chopped pecans evenly over the sugar mixture in the pan.
In a large bowl, mix the flour, granulated sugar, milk, eggs, vanilla extract, and baking powder until smooth. Pour the batter over the pecan topping in the pan.
Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cake to cool for a few minutes, then invert it onto a serving plate.
Serve warm or at room temperature.