Brush a standard 12-muffin tin with butter.

Layer two phyllo sheets with butter between. Sprinkle with half the sugar. Drizzle with butter. Layer two phyllo sheets on top, brushed with butter. Slice the sheet in half, lengthwise. Slice two times widthwise to form 6 rectangles.

Trim the corners to round the rectangles. Cut a slit/radius in each piece. Place in a muffin tin. Press to shape. Brush with butter and stuff each shell with leftover trimmings.

Repeat with remaining phyllo dough. Freeze the shells for 10 minutes.

Heat the oven to 350°F (175°C). Bake for 10 to 12 minutes, until golden and crisp. Halfway through, press the bottom of the shells to flatten.

In a saucepan over medium, add the purée. Cook, stirring frequently, 6 minutes, until the purée has thickened & a film forms on the bottom of the pan. Add the milk, pumpkin spice and bring to simmer.

In a bowl, whisk the yolks, cornstarch, sugar and salt. Stream in the hot milk while whisking. Return the mixture to the saucepan. Cook on medium, stirring frequently, until the mixture reaches a boil, 3 to 4 minutes. Once big bubbles come to surface, remove off heat.

Pour the custard through the mesh strainer. Whisk in the butter. Fill the pie shells. Chill in the fridge overnight.

In a pan over medium-high heat, add the sugar. Cook, stirring occasionally if needed, until the sugar reaches an amber color, about 6 minutes. Immediately pour the liquid sugar on top of each pie. Allow to set for a few minutes.

Heat the bottom of the pan using a blow torch or the stove top. Crack the top to help release from the pan.