Puree 1 pint (2 cups) halved berries in blender or food processor work bowl fitted with steel blade, scraping down sides as necessary, until smooth (you should have 1 1/4 cups; spoon off any extra). Bring puree, sugar, pectin, and a pinch salt to boil, stirring occasionally, in medium saucepan over medium heat. Increase heat to medium-high; boil hard until sugar and pectin are dissolved, about 1 minute. Off heat, skim foam from surface with large spoon.

Meanwhile, mix cornstarch and 1/4 cup cold water in small bowl until absolutely smooth. Off heat, add cornstarch slurry to strawberry mixture, then return to boil, stirring constantly, over medium heat. Reduce heat to medium-low and, continuing to stir constantly, simmer until mixture becomes thick and clear, about 3 minutes. Off heat, stir in cinnamon, lemon juice, and vanilla. Transfer glaze, reserving 1/4 cup for topping, into large bowl; cool to room temperature, at least 15 minutes.

Using a rubber spatula, fold sliced strawberries into large bowl of glaze, turning several times to coat thoroughly. Turn glazed berries into pie shell; spread evenly and smooth surface with rubber spatula. As in the photo, place berry halves in concentric circles, flat side down and pointed ends toward center, starting at center and working toward the outer edge. Stir 2 tablespoons water into reserved 1/4 cup glaze to thin; brush over berry halves to finish pie. Refrigerate until cold, at least 2, and up to 6, hours. Serve.

To preserve the shape of the strawberry, lay the berry on its side and slice it lengthwise into four or five pieces.