Heat oven to 375℉/190℃.
In a small bowl, combine cornstarch and 6½ Tablespoons water.
Whisk, or stir, until smooth. Set aside.
Combine cherries, 6 Tablespoons sugar, and 1 cup water in a large saucepan.
Bring to a boil, stirring often.
Stir in cornstarch mixture.
Cook until thickened.
Stir in ⅔ cup sugar, salt, lemon juice, almond extract, and vanilla.
Cook and stir over medium low heat until sugar is dissolved.
Strain out cherries. Set aside.
Return juice to saucepan.
Cook until thickened.
Pour over cherries.
Weave lattice across top.
Pinch edges of dough together to seal.
Brush with egg wash or heavy cream, if desired.
Bake for 75-80 minutes, until filling is bubbly and crust is golden brown.
Allow to cool completely and then refrigerate at least 1-2 hours (preferably overnight) before cutting.