Step 1: Preheat the Oven - Start by preheating your oven to 350°F (175°C) to ensure even baking.
Step 2: Prepare the Cookie Batter - In a large bowl, combine the butter flavored shortening and granulated sugar. Cream until light and fluffy. Add the egg and 2 teaspoons of vanilla extract, mixing well.
Step 3: Add Buttermilk and Hot Water - Gradually stir in the buttermilk and then mix in the hot water until smooth.
Step 4: Combine Dry Ingredients - In another bowl, whisk together the flour, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined.
Step 5: Fold in Fruity Pebbles - Gently fold in 1 cup of slightly crushed Fruity Pebbles into the batter.
Step 6: Scoop and Bake - Drop rounded tablespoons of batter onto parchment-lined baking sheets, leaving space between each. Bake for 10-12 minutes until edges are golden.
Step 7: Cool the Cookies - Allow cookies to cool on the baking sheet before transferring to a cooling rack.
Step 8: Make the Filling - Beat together the room temperature butter, sifted powdered sugar, 2 teaspoons of vanilla extract, and marshmallow cream until smooth. Fold in 1/2 cup of crushed Fruity Pebbles.
Step 9: Assemble the Whoopie Pies - Spread a generous amount of filling on the flat side of one cookie and top with another, pressing gently.
Step 10: Enjoy! - Serve immediately or chill for a firmer filling.
