Maple bacon scones

Ingredients

• ½ tsp vanilla extract
• 3 tbsp butter, melted
• 1½ tsp baking powder
• 3 tbsp maple syrup
• ¼ tsp baking soda
• ½ tsp kosher salt
• 3 cups all-purpose flour
• 2 tsp lemon zest
• 12 slices smoked bacon
• ½ cup butter (1 stick), cubed or grated (see note)
• ½ cup walnut or pecan pieces
• ½ cup heavy cream, cold
• 1 large egg, cold
• ½ cup maple syrup, cold
• 1 cup powdered (confectioner's) sugar