Step 1: Make the Green Cake

1. Preheat oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan.
2. Cream butter and sugar together until light and fluffy.
3. Add eggs one at a time, mixing well after each addition.
4. In a separate bowl, whisk together flour, baking powder, and salt.
5. Gradually add dry ingredients to the wet ingredients, alternating with milk.
6. Stir in vanilla extract and green food coloring until the batter reaches the desired shade.
7. Pour batter into the loaf pan and bake for 35–40 minutes, or until a toothpick comes out clean.
8. Cool completely, then slice into thick pieces and use a shamrock-shaped cookie cutter to cut out shamrocks.

Step 2: Make the Plain Pound Cake

1. Prepare another pound cake batter using the same method as above, omitting the green food coloring.

Step 3: Assemble the Cake

1. Grease and flour a 9×5-inch loaf pan.
2. Pour a thin layer of plain batter into the bottom of the pan.
3. Arrange the green shamrock cutouts in a row down the center, ensuring they fit snugly together.
4. Gently pour the remaining plain batter over the shamrocks, covering them completely.

Step 4: Bake and Serve

1. Bake at 350°F (175°C) for 50–60 minutes, or until a toothpick inserted in the center comes out clean.
2. Allow the cake to cool completely before slicing to reveal the hidden shamrock inside.