Cream butter and sugar, add eggs and beat well. Stir in the remianing ingredients, except filling. Set aside a small dish of batter. Drop the remainder by teaspoonsful on a greased cookie sheet. Make a well with the bowl of a spoon in each mound of cookie dough. Place a teaspoonful of filling in each well and drop a small dab of the reserved batter on top of the filling.
Bake 12 to 15 minutes in a preheated 375° oven.
Cream butter and sugar. Add eggs and lemon extract in 3 or 4 additions, beating well after each. Sift in the flour and baking powder. Add milk gradually and beat after each addition. Divide dough into 4 equal parts and chill.
Roll out 1/8 inch thick and cut into rounds. Place half the rounds on greased and floured cookie sheets. Place filling generously on each. With a small cookie cutter take centers out of remaining rounds, leaving thin rings of dough. Place one ring over each filled whole round. Press edges of each cookie firmly together. Dust tops with powdered sugar.
Bake 15 minutes in a preheated 375° oven.