1. Add flour, sugar, and salt to a large bowl and mix to combine. Add the diced butter and shortening to the bowl and mix a bit, then use a pastry cutter* and cut the fats into pea-sized pieces. Add the cold water gradually and mix in until the dough starts sticking together – you might not need all the water. Divide into two equal portions, wrap in plastic wrap, and place in the fridge for at least 1 hour.

2. Wash and dry the grapes. Remove all the stems or hard parts and cut them all in half. Place in a large pot, add the sugar, ground cinnamon, and lemon zest and mix to combine. Let sit for about 20 minutes so the grapes can marinate with the sugar. Mix the cornstarch with the lemon juice and add it to the pot. Heat everything up and stir until the liquids in the pot start to bubble and then thicken – takes about 2 minutes. Take off the heat and let cool down a bit.

3. Preheat the oven to 425°F (220°C). Roll out the first piece of dough on a floured surface slightly larger than a 9 inches (23cm) pie dish. Transfer to that pie dish and press to the bottom and sides – let overlap on the edges. Sprinkle the bread crumbs on the bottom of the crust. Pour the filling on top and smooth out. Roll out the second piece of dough and cover the grapes with it. Cut off overlapping dough and create a nice edge to seal the pie. You can roll out the remaining dough for some additional decorations. Make sure there are some holes/slits in the top of the pie so steam can escape. Place in the lower third of the oven and bake for 20 minutes, then reduce the heat to 350°F (180°C) and bake for 30-35 minutes longer. If the crust gets too dark cover with some aluminum foil – the pie should have a nice golden color though. Take out of the oven and let cool down completely.