Pre heat the oven to 180 degree C (356 degree F) for 10 minutes.
Take either two 6-inches (round or square) baking pans or one 8-inch baking pan. Grease entire surface of the pan with oil or melted butter using a brush.
Line the pan with a parchment paper (or butter paper).
Sift 1½ cups all purpose flour (maida) in a large bowl.
Add 1 cup plain curd, 250 ml condensed milk,1/3 cup milk,1tsp vinegar and 50 gms of powder sugar in another large bowl.
Mix well using a wired whisk until smooth. Add 1/2 teaspoon baking soda and 1 teaspoon baking powder.
Mix well and keep the mixture idle for 5 minutes. As the baking soda starts to react with the curd, bubbles will start to appear on the surface.
Add 3tbsp oil (Use any cooking oil ),3tbsp melted butter.
Add 1 teaspoon vanilla extract or vanilla essence and mix well.
Add previously sifted flour (maida).
Mix well using a wired whisk or a spatula.
Mix until it turns little smooth and no visible signs of white flour. Do not worry if the mixture is little lumpy.
Pour batter into previously greased pan. Place it in pre-heated oven and bake for 35-40 minutes at 180 C (356 F) until the top looks brown.
Remove the pan from the oven and insert a toothpick in the center to check whether it is fully cooked or not. If it comes out clean, then it means it is cooked. If it does not, then cook for few more minutes. If the cake turns brown from the top but remains uncooked from inside, cover the pan with aluminum foil to prevent cake from turning brown further and bake again for 5-10 minutes.
Let it cool for 15-20 minutes. Run a knife on sides of the pan. Place a cooling rack (or a plate) on the pan and invert both pan and rack to remove the cake from pan easily. Carefully remove the parchment paper. It will come out very easily.
For the Frosting:-
Cream the butter. Add the sugar and mix on high. Add the vanilla and salt. You can also add milk a tablespoon at a time to get a loosed consistency.
Divide the buttercream into two batches. For the colored batch, add the green food coloring, mix until combined then transfer to a piping bag. Once you have your two-tone piping bag ready, pipe and stack your layers.
Grab your piping bag filled with only the buttercream, snip off the tip and pipe a full layer all around and on top of your stacked layers.
Smooth out the buttercream on your cake using a bench scraper. Grab an angled cake spatula to smooth out the top and edges.
For the Christmas trees on the side of your cake, use a serrated knife to cut the ice cream cones into different sizes. Once you have a variety of desired sizes, carefully cut them in half and place them around the side of your cake.
Use a number 30 tip to pipe star-shaped dollops onto the surface of the cone beginning at the bottom and working to the top.
For the cones on top of your cake; go ahead and pipe those dollops on before placing them on your cake. You can save the “tippy top dollop” for after they are placed on the top of the cake.
When the trees are frosted, arrange them on the top of the cake, then go ahead and pipe that last dollop at the top of the cone.
Last, but not least, sift confectioners’ sugar onto the top of the cake and all on those trees and it’s ready to serve!