Before you begin assembling the baklava, trim the phyllo dough to the same size as your baking dish using a very sharp knife.
When not assembling the phyllo, be sure to keep it covered in plastic film with a damp towel over the plastic wrap to keep the dough from drying out. Also, be sure the damp towel or butter doesn't drip onto the phyllo dough- this could cause the sheets to stick together.
Use a pastry brush to grease the inside of your baking dish with a small amount of the melted butter.
Lay the first cut sheet of phyllo dough into the baking dish. Brush a thin layer of butter onto the sheet of phyllo and cover that sheet with a second sheet of phyllo. It may tear until you get the hang of its delicacy, just try to be light with your touch. Place a third sheet of phyllo on top of this buttered sheet.Continue this buttering of sheets until you have 10 sheets of phyllo, each separated by a thin layer of melted butter.
Sprinkle a handful (3/4 cup) of the ground nuts onto the surface of the phyllo. Spread out the nuts into an even layer using your fingers.
Repeat the process of assembling the layers by placing a sheet of phyllo onto the ground nut mixture. Lightly brush the phyllo with melted butter. Place another sheet of phyllo on top of the butter sheet. Repeat the buttering/layering until you have 5 sheets of phyllo this time.
Sprinkle another 3/4 cup of nuts, and begin the layering process over again (5 buttered sheets between each measurement of nuts).
After you've run out of the nut mixture, begin the final (10 sheet) layer of phyllo dough. If you have remaining sheets after you've placed the tenth sheet, save them for another recipe or discard them.
When fully assembled, you should have 6 layers of phyllo: 10 phyllo sheets>nuts>5 sheets>nuts>5 sheets>nuts>5 sheets>nuts>5 sheets>nuts>10 sheets.Brush the top sheet of phyllo with the remaining melted butter.