Preheat oven to 350 degrees F (175 degrees C).

In a bowl, combine flour, baking powder, baking soda, and salt.

In a separate bowl, beat sugar, sour cream, eggs, and vanilla until combined.

Gradually add the flour mixture to the wet ingredients, mixing until just combined.

Stir in the shredded apple and half of the chopped pecans.

Grease a loaf pan and pour the batter into it.

Sprinkle the remaining pecans over the top of the batter and press them lightly into it.

Bake for 55-60 minutes, or until a wooden skewer inserted into the center comes out clean.

If the top starts to brown too quickly, cover with foil towards the end of baking.

While the bread is baking, make the praline topping.

In a saucepan, combine butter and brown sugar.

Bring the mixture to a boil, stirring constantly, until the sugar is dissolved and the mixture is smooth.

Once the bread is baked, remove it from the pan and let it cool slightly.

Drizzle the praline topping evenly over the top of the bread.

Let the bread cool completely before slicing and serving.