Prepare the Flax Egg: In a small bowl, combine ground flaxseed with water to create a flax egg and set aside for about five minutes until it thickens.
Make the Cookie Dough: In a mixing bowl, beat together room temperature vegan butter with white sugar and brown sugar until fluffy. Add vanilla bean paste and the prepared flax egg, mixing until well combined.
Combine Dry Ingredients: In another bowl, whisk together all-purpose flour, baking powder, ground cinnamon (or pumpkin pie spice), and salt until evenly blended.
Mix Together Wet and Dry Ingredients: Gradually add the dry ingredients to the wet mixture while stirring until just combined; do not overmix.
Prepare Pecan Filling: In a saucepan over medium heat, melt vegan butter then stir in chopped pecans along with brown sugar, maple syrup, cornstarch mixture, and vanilla until it reaches a gooey consistency.
Assemble and Bake Cookies: Preheat your oven to 350°F (175°C). Roll cookie dough into balls then flatten slightly before placing on parchment-lined baking sheets; top each with a spoonful of pecan filling before baking for about 15-20 minutes or until edges are golden brown.