Preheat your oven to 350°F (175°C). Spray your loaf pan with vegetable cooking spray or use parchment paper for easy removal.
In a mixing bowl, whisk together the whole wheat flour, baking powder, baking soda, and salt.
In a separate bowl, combine the melted butter, unsweetened applesauce, and Lakanto Monkfruit Sweetener. Mix until well combined.
Beat the eggs one at a time and mix well into the bowl.
Stir in the vanilla extract, lemon extract or zest, lemon juice, and lemon zest.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
Gently fold in the Greek yogurt until the batter is smooth and well incorporated. Pour the batter into the prepared loaf pan and spread it evenly.
Bake in the preheated oven for about 45-50 minutes or until a toothpick inserted into the center comes out clean or with a few moist crumbs.
Allow the loaf to cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.