Step 1: Prepare the Cupcakes

1. Preheat the Oven: Set your oven to 350°F (175°C) and line a standard 12-cup cupcake pan with paper liners.
2. Cream the Butter and Sugars: In a large mixing bowl, use a hand or stand mixer to cream together the softened butter, brown sugar, and granulated sugar. Beat until the mixture is light and fluffy, about 2-3 minutes.
3. Add the Wet Ingredients: Beat in the eggs one at a time, ensuring each is fully incorporated. Mix in the vanilla extract and maple syrup until the mixture is smooth and well-combined.
4. Prepare the Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
5. Alternate Mixing: Gradually add the dry ingredients to the butter mixture in three additions, alternating with the buttermilk in two additions. Begin and end with the dry ingredients. Mix just until combined, being careful not to overmix.
6. Fold in Pecans: Gently fold in the toasted chopped pecans with a spatula to distribute them evenly throughout the batter.

Step 2: Make the Brown Sugar Crumble Topping

1. Combine the Ingredients: In a small bowl, combine the flour, brown sugar, softened butter, chopped pecans, and cinnamon. Use a fork or your fingers to mix until the mixture forms a crumbly texture.

Step 3: Assemble and Bake

1. Fill the Cupcake Liners: Divide the cupcake batter evenly among the prepared liners, filling each about 2/3 full.
2. Add the Crumble Topping: Generously sprinkle the brown sugar crumble topping over each cupcake.
3. Bake: Place the cupcake pan in the preheated oven and bake for 18-20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.
4. Cool: Remove the cupcakes from the oven and allow them to cool in the pan for 5 minutes. Transfer them to a wire rack to cool completely.

Step 4: Serve

1. Presentation: Once cooled, the cupcakes are ready to serve as is or can be paired with additional toppings like whipped cream or a light maple glaze for extra indulgence.
2. Enjoy: Serve as a delightful dessert, snack, or treat for special gatherings or everyday celebrations.