Set your oven to 350°F (175°C). Lightly grease an 8x8-inch baking pan or line it with parchment paper for easy removal.
In a spacious bowl, mix together the pumpkin puree, softened vegan butter, maple syrup, and vanilla extract. Stir until smooth and well-mixed.
In a separate bowl, mix the flour, baking soda, salt, cinnamon, nutmeg, cloves, and allspice until thoroughly blended.
Slowly incorporate the dry ingredients into the wet mixture, stirring lightly until just combined. Add the plant-based milk and mix until the batter becomes smooth and thick.
Transfer the batter into the prepared pan, smoothing it out into an even layer.
Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean but slightly moist.
Allow the bars to cool entirely in the pan before slicing them into squares.
Serve and enjoy!