Preparation

Preheat oven to 425 degrees.

In a small bowl, whisk together 1 cup sugar and cornstarch.

In a medium bowl, toss raspberries with lemon juice; add sugar mixture and stir to combine.

Place a pastry shell in a 9-inch pie dish. Add in berry filling. Top with second shell—either solid with slits cut in or woven into a lattice pattern—crimping edges with your fingers or a fork to seal.

In a small bowl, gently whisk egg with remaining sugar until just combined. Paint mixture onto top shell, taking care to avoid the outer edge.

Bake 15 minutes at 425; then reduce oven temperature to 375 and bake 25 to 35 minutes longer.

The pie is ready when the filling has been boiling for at least 5 minutes.

Optional Topping:
Dust the top crust with a sprinkling of large sugar granules before baking. Or forgo the second shell altogether and opt for a cobbler-style nut-crumb topping instead.