Preheat the oven to 375°F (190°C) and place the oven rack in the center position.
In a bowl, beat together the sugar and margarine using an electric mixer on medium speed until creamy and smooth.
Beat in the eggs, one at a time, on high speed until incorporated, then mix in the vanilla extract.
In a separate bowl, mix the flour, baking powder, and salt.
Gradually stir the flour mixture into the wet ingredients, alternating with milk, until just incorporated.
Spoon the batter into each ice cream cone, filling them to within 1/2-inch from the top. Place the filled cones on a baking sheet.
Bake in the preheated oven for 15-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow to cool before serving.