Allow ½ cup plant-based butter and 1 egg to come to room temperature.

Preheat the oven to 350°F and line a rimmed cookie sheet with parchment paper or a silicone baking mat and set aside.

Measure ½ cup of pumpkin puree. Using a cheesecloth or a clean dish towel, squeeze out the extra moisture from the pumpkin puree. You won't get all of the liquid out, but as much as you can.

In the base of a stand mixer fitted with the paddle attachment (or in a large bowl with handheld beaters) cream together plant-based butter, pumpkin puree, ⅓ cup granulated sugar, and ½ cup brown sugar.

Add room temperature egg and 1 teaspoon vanilla and mix to combine.

In a medium mixing bowl, stir together ¾ cup flour, ¾ teaspoon baking soda, ½ teaspoon pumpkin pie spice, ¼ teaspoon cinnamon, ¼ teaspoon salt, ¾ cup quick oats, and ½ cup old fashioned oats.

Slowly spoon the dry ingredients into the wet ingredients and mix to combine.

Using a 1.5 Tablespoon cookie scoop, scoop out the dough onto the prepared baking sheet.

Bake for 14 minutes. Remove from oven and allow to cool completely before filling with icing.

While the cookies cool, beat together plant-based butter, marshmallow fluff, powdered sugar, vanilla, and salt. Transfer the frosting to piping bag or a gallon zip lock and chill until ready to ice.

Flip half the cookies over so the flat side is up, pipe a circle of icing on the flat side and top with a non-iced cookie. Repeat to make all of the oatmeal cream pies.

Serve immediately or chill until you are ready to serve.

Keep dairy-free pumpkin spice oatmeal cookies in an air-tight container in the refrigerator until you are ready to serve or enjoy!