Let’s break down the process into easy-to-follow steps.

Step 1: Prepare Oven and Pan. Preheat the oven to 350°F (175°C). Grease a 9-inch square baking pan.

Step 2: Cream Shortening and Sugar. In a bowl, cream together the sugar and shortening until light and fluffy.

Step 3: Add Egg and Vanilla. Add the egg and vanilla extract; beat well.

Step 4: Combine Dry Ingredients. Combine the flour, baking powder, and salt in a separate bowl.

Step 5: Alternate Dry and Wet Ingredients. Gradually add the dry ingredients to the creamed mixture, alternating with the milk, beating well after each addition. Begin and end with the dry ingredients.

Step 6: Bake. Spread the batter evenly in the prepared pan. Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.  

Step 7: Cool. Cool the cake completely on a wire rack.

Step 8: Whip Cream. Whip the heavy cream until stiff peaks form. Traditionally, a little powdered sugar and vanilla extract would be added to the whipped cream, but the recipe omits this. You can certainly add them to taste.

Step 9: Assemble Shortcakes. Cut the cooled cake into 9 pieces. Split each piece horizontally.

Step 10: Layer and Serve. Fill each split cake piece with whipped cream and sliced strawberries. Replace the top of the cake. Garnish with a dollop of whipped cream and additional berries. Serve immediately.

These steps are very simple and easy to follow.