Preheat the oven to 350°F (175°C). Grease and line a baking sheet with parchment paper.

In a mixing bowl, cream together the softened butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In another bowl, whisk together the flour, baking powder, and salt. Gradually add to the butter mixture, mixing until just combined.

Spread the batter evenly onto the prepared baking sheet and bake for 15-20 minutes, or until a toothpick comes out clean.

Allow to cool completely before cutting into small squares or rectangles.

In a bowl, mix the powdered sugar, milk, and vanilla extract until smooth. Adjust milk for desired consistency.

Dip each cake piece into the icing, allowing excess to drip off. Place on a wire rack to set.

For chocolate-coated petit fours, melt the chocolate and dip the iced cakes into the chocolate, then let set.