In a large saucepan, melt the butter over low heat until smooth.
Add the miniature marshmallows to the saucepan. Stir constantly until the marshmallows are completely melted and smooth.
Remove the saucepan from the heat. Stir in the vanilla extract and salt.
Add the Rice Krispies cereal to the melted marshmallow mixture. Gently fold the cereal into the marshmallow mixture until it’s evenly coated.
Lightly grease a 9×13 inch baking pan with butter or cooking spray. Pour the Rice Krispie mixture into the prepared pan. Using a spatula or your fingers (lightly greased!), gently press the mixture evenly into the pan.
Let the Rice Krispie treats cool completely in the pan before cutting (about 30 minutes to an hour).
In separate microwave-safe bowls, melt each color of candy melts according to the package directions (usually in 30-second intervals, stirring in between). If the candy melts are too thick, add a small amount of vegetable shortening (about 1/2 teaspoon at a time) to thin them out.
Once the Rice Krispie treats are completely cooled, drizzle the melted candy melts over the top.
While the candy melts are still wet, sprinkle the Easter-themed sprinkles over the top.
Gently press jelly beans, chocolate eggs, or Peeps into the melted candy melts.
Let the candy melts set completely before cutting the Rice Krispie treats (about 30 minutes to an hour). You can speed up the process by placing the pan in the refrigerator for a few minutes.
Once the candy melts are set, cut the Rice Krispie treats into squares or shapes.
Serve the Easter Rice Krispie treats immediately, or store them in an airtight container at room temperature for up to 3 days.
Notes
Use Different Cereals: You can substitute other cereals for Rice Krispies, such as Cocoa Krispies or Fruity Pebbles.
Add Food Coloring: You can add a few drops of food coloring to the melted marshmallow mixture to create colorful Rice Krispie treats.
Use Different Extracts: You can substitute other extracts for vanilla extract, such as almond extract or lemon extract.
Make Rice Krispie Treat Pops: Insert lollipop sticks into the Rice Krispie treats before the candy melts set to make Rice Krispie treat pops.
Add Peanut Butter: Stir in 1/2 cup of peanut butter to the melted marshmallow mixture for a peanut butter flavor.
Make a Chocolate Drizzle: Melt some chocolate chips and drizzle them over the top of the Rice Krispie treats for a chocolatey treat.
Use Different Sprinkles: Experiment with different types of sprinkles to create unique and festive designs.
Add Dried Fruit or Nuts: Stir in dried fruit or nuts to the Rice Krispie mixture for added texture and flavor.
Make Mini Rice Krispie Treats: Use a mini muffin tin to make individual mini Rice Krispie treats.
Use a Different Pan Size: If you want thicker Rice Krispie treats, use a smaller pan. If you want thinner Rice Krispie treats, use a larger pan.