In a large bowl, combine flour, baking powder, and salt. Using a pastry blender, cut in shortening until mixture is crumbly. Add the half-and-half, stirring with a fork until the mixture is just barely combined.
Turn dough out onto a floured surface; knead 6-8 times, until dough forms a ball. Roll 1/3 of the pastry into 1/4-inch thickness and cut into strips 1 1/2-inches wide (reserve the rest of the dough). Place on a parchment-lined baking sheet and bake for 10 minutes or until lightly browned.
Make the filling:
Reduce oven temperature to 350 degrees.
In a large bowl, combine the berries, sugar, flour, lemon juice, vanilla and almond extract. Let stand until sugar dissolves. Spoon half of the mixture into a greased 13x9-inch baking dish. Break the baked pastry strips into pieces and lay on top of the fruit mixture; top with the remaining berries. Dot with the butter.
Roll the remaining pastry dough into 1/4-inch thickness and cut into 1-inch wide strips. Weave into a lattice over the filling. If desired, brush the pastry with additional half-and-half and sprinkle with sugar.
Bake for 50 minutes or until bubbly and golden.
Notes
Half-and-half is a mixture of half cream, half whole milk. If you do not have access to half-and-half, feel free to use milk instead.