Preheat the oven to 350F and line a muffin pan with 7 cupcake liners. Finely grate the carrots and set aside.
Add the oat milk and apple cider vinegar to a small bowl and let sit for 1-2 minutes until milk starts to curdle. This forms the vegan buttermilk. Then, add in the grated carrots, white sugar, brown sugar, olive oil, and vanilla. Whisk together.
Next, add in the all-purpose flour, cinnamon, baking powder, baking soda, and salt. Make sure to add the flour first and pile the other dry ingredients on top so they get mixed in evenly. Mix everything together until all the streaks of flour are gone and you have a thick batter. I highly recommend using a whisk when mixing cupcake batter to avoid over-mixing.Then, gently fold the crushed pecans into the batter.
Fill the cupcake liners with the carrot cake batter until they are about ⅔ full. Then, add to the oven and bake for 18-22 minutes (for my oven, 20 minutes is the perfect time).
Remove the cooked cupcakes from the oven and immediately transfer to a wire rack to finish cooling. Don't let them sit in the hot muffin tin when cooling or they could overcook/become soggy on the bottom.
Once the cupcakes have cooled, make the maple frosting.
Add the vegan butter and maple syrup to a large mixing bowl and use an electric/standing mixer to beat together until fluffy, about 3-5 minutes. Then, gradually add in the powdered sugar ½ cup at a time until the frosting has reached your desired sweetness. Continue beating the frosting another 3-5 minutes until it is super fluffy and becomes light in color.
Add the maple frosting to a piping bag and pipe onto the cooled cupcakes. Top with additional crushed pecans, a dash of cinnamon, and serve!