In a large bowl, combine flour, 2 teaspoons white sugar, baking powder and salt.
Cut in 1/4 cup butter and lard until mixture resembles coarse crumbs. Blend egg yolk and milk, add to flour mixture and stir until mixture forms a ball. Pat onto the bottom and about 1 inch up the sides of an 8x12 inch baking pan. Arrange apple wedges in rows lengthwise on top of dough. Cover with streusel.
To make the streusel: In a medium bowl, combine 1/2 cup white sugar, 1/4 cup brown sugar, cinnamon and 1 1/2 tablespoon flour.
Cut in butter and blend into coarse meal.
Bake in the preheated oven for 60 minutes. Cover with foil the last 25 minutes to prevent over browning.