Preheat your oven to 350°F (175°C).
In a mixing bowl, whisk together the flour, baking soda, cinnamon, and salt.
In another bowl, whisk together the vegetable oil, brown sugar, and eggs until well combined.
Add the grated carrots, crushed pineapple, and vanilla extract to the wet mixture and mix well.
Gradually add the dry ingredient mixture to the wet ingredients, stirring until just combined.
Drop rounded tablespoons of batter onto a baking sheet lined with parchment paper.
Bake for 10–12 minutes, or until a toothpick inserted comes out clean.
Allow the cakes to cool on the baking sheet for a few minutes before transferring them to a wire rack.
In a mixing bowl, beat the softened cream cheese, powdered sugar, and vanilla extract for the filling until smooth.
Spread or pipe the cream cheese filling onto the flat side of half of the whoopie pies, then sandwich with the other half.
Serve and enjoy your carrot cake whoopie pies!