Preheat oven to 170 °Celsius.

Beat butter and sugar till soft and creamy for about 2 minutes. Add eggs, one at a time, beating well after each addition.

In a separate bowl, sift flour, baking powder, and salt. Fold in the sifted ingredients into the creamed mixture alternately with milk, starting and ending with flour.

Finally, add in vanilla essence and combine well. Pour batter into two greased and floured cake pans and bake for 45 to 50 minutes until the top of the cake springs back when lightly pressed. The cakes are done when a skewer inserted in the center of the cake comes out without any wet batter.

Remove cakes from oven and let them cool completely before icing and decorating.

Draw the number '1' on a piece of A3 paper. This will be the template used to cut the cake into number '1' shape.

To optimize the cake, split the template into 2 and carve the cake in 2 sections. The long vertical part of the number ‘1’ to form the first part. And the horizontal base of the number ‘1’ is to form the second part.

Carve the cake with the template as a guide. After that, join the piece together with buttercream and give the entire cake a smooth buttercream crumb coat.

Next, roll some pink fondant and cut out the full number '1' as per the paper template. Gently roll the cut fondant into a rolling pin and unroll it onto the cake top.

After that, roll some darker pink fondant. Roll it into a long strip, enough to covered the entire sides of the cake. Make sure the width of the strip is as tall as the cake. Gently roll the strip onto your rolling pin and unroll it onto the sides of the cake. Trim off excess fondant at the top and bottom.

For the cake border, pipe out a long thin roll of dark pink fondant using the extruder tool. Attach it all around the base of the cake with shortening.

The Minnie Mouse image is printed on an edible paper. Cut the image following its outline and attach it onto a thinly rolled piece of white fondant. Cut the fondant out and let it firm up before attaching it to the cake top. You can use shortening to help the image stick to the cake.

For the cupcake, draw it on a piece of paper. Use the paper as a template to cut out the outline of the cupcake on white fondant. Use food colors to paint the cupcake and the candle and draw the black outline with an edible food marker. Cut the cupcake out of the fondant and attach it to the cake with shortening.

Cut out white polka dots with a round cutter and attach them to the cake. For consistent spacing, arrange them in a pattern. Similarly, cut pink polka dots in fondant and attach them to the cake board.

Complete the cake decoration with the tiny flowers and the matching green leaves. Use a small oval cutter to cut out the leaves. And then pinch one end of the cutouts to form the leaves. Attach these to the cake with shortening.