Crust: Mix together the ingredients for the crust, using a pastry blender or two knives, until the mixture resembles meal. Press the crust into an 8x8 inch pan and bake for 20 minutes in a 350 oven.
Topping: Beat together the eggs, sugar, and vanilla. Mix the flour, baking powder, and coconut and add to the egg mixture, beating until smooth. Add the lemon juice and stir in the nuts. Pour the mixture over the crust and return the pan to the oven for 35 minutes. When cool, cut into bars.