Preheat the oven to 350 degrees. Lightly grease a 9x5x3-inch loaf pan. Set aside.
In a large bowl, using an electric mixer, beat together the sour cream, sugar, eggs and vanilla on low speed for a 2 minutes until well blended. Stop the mixer and then add in the flour, cinnamon, baking powder, baking soda and salt. Continue to beat on low until well combined.
Fold in the apples and half the nuts into the batter. Transfer the batter into the greased loaf pan.
Sprinkle the rest of the nuts on top and then press them lightly into the batter. Bake for about 60 minutes or until a toothpick inserted into the center comes out clean.
Cool in the loaf pan for about 20-30 minutes and then transfer to a wire rack to cool completely.
Praline Sauce: In a small saucepan, over medium heat, bring the butter and brown sugar to a boil. Lower the heat and then simmer for about one minute, stirring constantly until the sauce thickens. Remove from heat and drizzle over the bread. Cool completely.