Preheat the oven to 350 degrees Fahrenheit. Place a pan filled with water on the lowest rack.
Place the tofu and cream cheese in a food processor and process until smooth.
Add the pumpkin, sugar, cinnamon, nutmeg, vanilla and salt and process for a few more seconds or until you have a velvety mousse.
Line a 12-cup cupcake tin with paper liners.
Divide the batter evenly among the cups. Smooth the tops with a spatula.
Bake for 25 minutes or until the cupcakes have firmed up and the sides are a slightly deeper orange than the center.
Remove to a rack, cool. and then place the cupcake tin in a refrigerator until the cupcakes are chilled. This will make it easier to unmold the cupcakes. When the cupcakes are chilled, remove them. Tilt the tin and give it a little shake if necessary and they will slide right out.
Make the buttercream:
Place the vegan butter in a bowl and whisk with a hand mixer or in a stand mixer until it's light and fluffy, about two minutes.
Add the vanilla, lime juice, and the sugar, half a cup at a time, beating well to incorporate after each addition. Scrape down the bottom and sides of the bowl frequently to ensure everything's well-mixed.
Using a pastry bag or a spatula, spread some of the icing on top of each chilled cupcake. Crumble some delicious vegan cookies on top, like my Amaretti Cookies.