
4 large eggs
½ (14.1-ounce) package refrigerated piecrusts (1 piecrust)
1½ cups heavy whipping cream
12 ounces 86%-cacao intense dark chocolate bars, chopped
⅔ cup salted butter, softened
1½ cups granulated sugar, divided
½ cup warm water
1 tablespoon fresh lemon juice
1 teaspoon vanilla extract
½ teaspoon cream of tartar