Remove the husk from the 1 ear of corn and cut the kernels off. Save the cob to simmer with the cream.
In a nonstick skillet, melt the 1 tablespoon unsalted butter and saute the corn kernels until they have a few brown specks on them. Reserve 2 tablespoons to use as a garnish.
Move an oven rack to the middle position and preheat the oven to 325°F (165°C).
In a medium-sized saucepan heat the 2 cups heavy whipping cream, corn cob, and 2 sprigs of fresh thyme over medium-high heat until it begins to simmer. The corn cob will impart additional corn flavor to the cream. Remove the saucepan from the heat and allow the cream to steep for 15 minutes. Remove the corn cob and thyme and stir in the sauteed corn and 1 teaspoon vanilla extract. Puree with an immersion blender until smooth.
In a medium-sized bowl whisk together the 3 egg yolks, ½ cup granulated white sugar, and ⅛ teaspoon kosher salt until smooth and the egg yolks start to lighten in color.
Continuously whisk the yolks while you slowly pour in the warm cream.
Lay a towel across the bottom of the pan and arrange your ramekins on top. The towel will keep the ramekins from sliding around.
Pour the custard into the ramekins. Place the pan in the oven and then pour hot water into the pan, careful not to splash water into the ramekins. The water should come about halfway up the ramekins. Bake for 20 to 30 minutes until the edges are set but the centers are still slightly jiggly. The baking time will vary depending upon the size of your ramekins.
Remove the baking dish from the oven and allow the custards to cool for approximately 15 minutes until you can safely pick up the ramekins and remove them from the water. Allow the custards to cool on the counter for an additional 15 minutes. Cover each ramekin with plastic wrap and chill them in the refrigerator for at least four hours and up to four days.
Remove the custards from the refrigerator and evenly sprinkle each custard with 1 teaspoon of granulated sugar. Ignite your torch and hold the flame about 4 inches from the surface of the custard. Using a circular motion heat the sugar until it browns and forms a crust.