Preparation
Have all the ingredients at room temperature.
To make the cake, position a rack in the lower third of the oven and preheat to 325. Grease and flour a bunny cake pan; tap out excess flour.
Over a sheet of waxed paper, sif together the flour, baking powder and salt, set aside.
In the bowl of an electric mixer fitted with the flat beater, beat the butter on medium speed unti creamy and smooth, about 30 seconds. Add granulated sugar and continue beating until light and fluffy, about 5 minutes, stopping the mixer to occasionally scrape down the sides of the bowl. Add the eggs a little at a time, beating well after each addition. Beat in the vanilla until just incorporated, about 1 min.
Reduce the speed to low and add the flour mixture in three additiona, alternating with the milk and beginning and ending with the flour. Beat ea. addition just until incorporated, stopping to scrape down the sides of the bowl. Spoon the batter ino the prepared pan, spreading the batter so the sidesare higher than the center. Bake until the cake begins to pull away from the sides of the pan and toothpick comes out clan, 35 to 38 minutes.
Transfer the pan to a wire rack and let cake cool upright for 15 min. Invert the pan onto the rack and lift off the pan. Let cake cool completely, at least 2 hours, before serving or decorating.
To make the buttercream, in a bowl wih a flat beater, combine the confectioner's sugar, butter, 7 tbs milk, vanilla and salt an beat on medium speed until creamy and smooth, about 2 min. If the frosting is too dry, add more milk, 1 tsp at a time, until it is creamy but still holds peaks.
If not using the buttercream immediately. cover with plastic wrap, pressing it directly on the surface to prevent a skin from forming, and refrigerate up to 4 days. Bring to room temperature and beat again with a mixer before using.
To assemble and decorate the cake, wash and thoroughly dry the pan, then return both halves of the cooled bunny cake to the pan. Level the cake by using a serrated kinfe to gently saw off the part of each cake that rose above the edge of the pan.
Remove 1 cake half from the pan. Spread a layger of buttercream over the top of the cake half that is still in the pan. Place the other cake half on top, pressing down firmly to secure the 2 halfs. Using a paper towel, wipe off any excess buttercream. Let stand for 10 min. Remove the cake from pan by lifting pan vertically and tilting it forward, then catching the cake with your hand. Set the cake on its side on a piece of parchment paper, taking care to keep the 2 halves aligned.
Fill a small fine-mesh sieve half full with confectioner's sugar and lightly sprinkle over the side of each cake. Carefully turn the bunny on its other side, being careful not to smudge the sugar. Lightly sprinkle the 2nd side with sugr, then set the bunny upright on a platter and dust the top. Dust the egg cake halves with ugar and transfer to the platter.