Preheat oven and liners:

Set oven to 350°F (175°C). Place liners in a muffin pan.

Mix batter and bake:

Using an electric mixer, cream butter and sugar in a bowl until light and fluffy, about 1-2 minutes. Beat in egg whites, sour cream, milk, and vanilla just until combined. In another bowl, whisk together flour, baking powder, and salt; sift. Gradually add the dry mixture to the wet, stirring until just incorporated. Fill each liner halfway. Bake for 17-19 minutes at 350°F (175°C) until a toothpick inserted into the center emerges with a few moist crumbs. Let cool fully before frosting. While they cool, prepare the dinosaur spikes.

Melt almond bark:

Coarsely chop the vanilla almond bark. Microwave in a safe bowl at 50% power, stirring now and then, until fully melted.

Tint and pipe spikes:

Split the melted almond bark into 3 bowls; tint each with gel coloring. Pour each color into a squeeze bottle. On a baking sheet lined with a silicone mat or parchment, pipe small triangles. Optionally add sprinkles. Allow to harden completely before detaching spikes.

Make buttercream frosting:

Beat butter and vanilla with an electric mixer in a bowl until fluffy, 1-2 minutes. Slowly add powdered sugar, mixing on low until smooth. Adjust sweetness to taste. If too thick, add a splash of milk or cream. For extra lightness, incorporate ¼ cup heavy cream with the final portion of sugar and whip for 3-4 minutes.

Color and bag frosting:

If making two colors, split the frosting, add coloring, and beat until uniform. Transfer each to a piping bag fitted with a Wilton 1M tip.

Frost and add spikes:

Pipe frosting onto cooled cupcakes. Place 5 spikes on each, alternating front and back for the best look.