Creating the Speckled Egg Buttercream Cake is simple if you follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and grease and flour two 9-inch round cake pans.
2. Mix Dry Ingredients: In a large bowl, sift together the flour, baking powder, and salt.
3. Cream Butter and Sugar: In a separate bowl, cream together the softened butter and granulated sugar until light and fluffy.
4. Add Eggs: Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next.
5. Combine Wet Ingredients: Stir in the vanilla extract and milk until the mixture is smooth.
6. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined and smooth.
7. Pour Batter: Divide the batter evenly between the prepared cake pans.
8. Bake: Place the pans in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
9. Cool Cakes: Remove the cakes from the oven and let them cool in the pans for 10 minutes. Then, transfer to wire racks to cool completely.
10. Prepare Buttercream: In a medium bowl, beat the softened butter until creamy. Gradually add the powdered sugar, alternating with heavy cream, until the desired consistency is reached. Mix in the vanilla extract.
11. Color the Frosting: Divide the frosting into small bowls and color each with different pastel shades for speckling.
12. Frost the Cake: Once the cakes are completely cool, place one layer on a serving platter. Spread a layer of buttercream frosting on top, then place the second layer on top.
13. Decorate: Use a spatula to frost the top and sides of the cake with a smooth layer of buttercream. Using a pastry bag with a speckled decorating tip, pipe small dots of colored frosting all over the cake for the speckled effect.
14. Add Final Touches: If desired, sprinkle edible glitter or sprinkles on top for added decoration.

These steps will guide you in creating this incredible cake effortlessly.