Preheat oven to 350F. Grease muffin tin or line with muffin liners.
In a large bowl, sift flour, baking powder, baking soda and salt. Mix well.
In the bowl of an electric mixer fitted with the paddle attachment, mix eggs and sugar until well combined. Gradually add oil and vanilla, mix until just blended.
With the mixer on low, slowly add half the flour mixture; mix until just blended. Add the buttermilk, mix until just blended. Slowly add remaining flour mixture, scraping down sides of the bowl with a spatula, as necessary, until just blended.
Divide batter evenly among prepared muffin cups. Transfer muffin tin to oven and bake for 8 to 10 minutes. Transfer muffin tin to a wire rack and let cupcakes cool completely.
To prepare the frosting, beat butter for a few minutes with a mixer with the paddle attachment on medium speed. Add powdered sugar and turn your mixer on the lowest speed until the sugar has been incorporated with the butter. Increase mixer speed to medium and add vanilla extract and cream. Then beat for another 5 to 8 minutes until light and fluffy.
Reserve 1/4 cup frosting and tint it with red coloring. Transfer to a pastry bag fitted with a very small round tip.
Reserve 1/2 cup frosting and tint it with green coloring. Transfer to a pastry bag fitted with a small star tip.
Smear the white frosting on top of each cupcake. Pipe small green stars around the edges. Then small red dots on top of each star. Finish with a red small bow.