Preheat the oven to 350°F and line two baking sheets with parchment paper.

Whisk together the flour, Milo, baking powder and salt in a bowl and set aside.

In another bowl using an electric mixer, cream the butter and sugar for about 4 minutes, or until smooth. Add the egg, beating for 1 more minute. Add the vanilla. Reduce the mixer speed to low and add the dry ingredients and the milk, mixing only until they are incorporated. Using a wooden spoon or rubber spatula, mix in the chocolate chips.

Drop about 1 tablespoon of dough onto the sheets, leaving about 2 inches of space between them. Bake for about 12 minutes, until set but still soft when touched.

Remove from the oven and let the cookies cool on the baking sheet(s) on a wire rack for about 3 minutes. Transfer the cookies to the rack and let cool completely. Store in an airtight container at room temperature for up to 3 days.