Preheat oven to 350°F (175°C). Grease and flour three 8-inch (20 cm) round cake pans. In a bowl, whisk together flour, baking powder, and salt. In another bowl, cream butter and sugar until light and fluffy. Beat in eggs one at a time, then add vanilla. Alternate adding dry ingredients and milk, beginning and ending with dry. Divide batter evenly among pans and bake for 25–28 minutes, until a toothpick comes out clean. Cool completely on a wire rack.

In a saucepan, heat cream with vanilla until steaming. In a bowl, whisk yolks, sugar, and salt. Slowly pour the hot cream into the yolk mixture, whisking constantly (tempering). Return mixture to the saucepan and cook over low heat, stirring, until thick enough to coat the back of a spoon. Strain and let cool completely.

In a heavy-bottomed saucepan, melt sugar over medium heat without stirring until golden. Add butter and stir. Pour in cream and salt, simmer for 2–3 minutes until smooth. Cool slightly.

Place one cake layer on a serving platter. Spread half of the cream over it, sprinkle with half the pecans. Add the second cake layer, remaining cream, and more pecans. Top with the third cake layer. Pour caramel glaze over the cake, letting it drip down the sides.

Sprinkle an even layer of sugar over the caramel-coated top. Using a kitchen torch, melt and caramelize the sugar until crisp. Let cool for a few minutes before slicing.