Pastry Cream
1 1/2 cups heavy whipping cream
3 egg yolks
1/2 cup sugar
pinch salt
1 tablespoon + 1 teaspoon cornstarch
2 tablespoons butter, cold and cut into 2 pieces
1 1/2 teaspoons vanilla extract
Cupcakes
1 3/4 cups flour
1 1/2 teaspoons baking powder
3/4 teaspoon salt
1 cup sugar
12 tablespoons cool butter, cut into 12 pieces
3 eggs
3/4 cup milk
1 1/2 teaspoons vanilla extract
Glaze
3/4 cup heavy whipping cream
1/4 cup light corn syrup
8 ounces bittersweet chocolate
1/2 teaspoon vanilla extract

Pastry Cream
Heat cream over medium heat till simmering, stirring occasionally. Whisk egg yolks, sugar and salt together. Add cornstarch and whisk till mixture is pale, yellow and thick, about 15 minutes. When cream reaches full simmer, slowly whisk it into yolk mixture. Return mixture to saucepan and cook over medium heat, whisking constantly, till thick and glossy, about 1 1/2 minutes. Off heat, whisk in butter and vanilla. Transfer cream to small bowl, press plastic wrap directly on surface and chill till cold and set, at least 2 hours and up to 2 days.
Cupcakes
Heat oven to 350°F. Spray muffin pan with nonstick cooking spray, flour generously and tap out excess flour. Combine dry ingredients. Add butter, one piece at a time, and cut in till mixture resembles coarse sand. Add eggs, one at a time, and mix till combined. Add milk and vanilla and mix till light and fluffy and no lumps remain. Fill cups 3/4 full. Bake till toothpick inserted comes out clean, 18-20 minutes. Cool in pan 5 minutes and turn out onto rack to cool completely.
Glaze
Heat all ingredients together over medium heat, stirring constantly, till smooth. Set aside to cool and thicken for 30 minutes.
Assembly
Cut a cone shaped piece from the top of each cupcake. Cut away all but 1/4 inch thickness of the top of the cone. Fill the cupcake with 2 tablespoons of pastry cream and top with the disc of cake. Set filled cupcakes on a rack. Spoon 2 tablespoons glaze over each cupcake, allowing it to drip down sides. Chill 10 minutes till just set. Store in refrigerator up to 2 days, bringing to room temperature before serving.
Nicole's Note
These can be made in cupcake liners as well, but the glaze needs to be firmer before putting on the cupcakes as letting it run down the sides does no good. Putting water in the empty muffin cups makes the oven moister so it may have effected the consistency of the cupcakes. I used the food processor to crumb the butter into the dry ingredients. The cupcakes were seemingly very buttery on the bottom, causing the liners to be greasy. Overall, very good taste and texture.