Base: In a medium bowl, mix together flour, baking powder, and salt.
In a large bowl beat butter and sugar until smooth and creamy. Beat in egg and vanilla until incorporated. Blend in flour mixture, just until a dough forms. Spread dough evenly in pan. Bake in preheated oven for 6 to 7 minutes, until lightly browned.
Topping: Arrange apricots evenly over top of base. Sprinkle with sugar and cinnamon.
Bake 10 to 12 minutes longer or until golden brown.Place pan on a wire rack to cool completely, then cut into squares.