Preheat the oven to 375 degrees and grease a 9 x 13 inch baking pan.

For the dough: In a large bowl (or your food processor), mix together the flour, sugar, baking powder and salt. Use a pastry blender to cut in the butter until the butter is the size of small peas. Add the egg and continue to cut in the dough. The dough will be crumbly. Pour half of the dough into the pan and press down until firm. Refrigerate pan and remaining dough while you make the filling.

For the filling: Place the diced peaches in a large bowl and add the remaining ingredients. Mix until the dry ingredients are evenly coated on the peaches. Spread this mixture evenly over the crust. Crumble the remaining dough over the peach layer.

Bake for 45 minutes, until top is slightly browned. Cool completely before slicing into bars.