Pre-bake the tartlet shells if they are not already done. If using homemade shells, blind bake them at 350°F for 15 minutes with weights. After that, remove the weights and bake for an additional 5 minutes.

In a small saucepan, melt the butter over medium heat until it foams and turns golden brown with a nutty aroma. Set aside to cool slightly.

In a bowl, whisk together the egg yolks, sugar, and cornstarch until smooth.

In a separate pan, heat the milk and cream until steaming. Slowly pour this mixture into the egg mixture while whisking constantly.

Return the mixture to the heat and cook over medium heat, stirring constantly, until it thickens. This should take about 5–7 minutes.

Remove from heat and stir in the browned butter, vanilla paste, and salt. Pour into a bowl and press plastic wrap directly on the surface. Chill in the refrigerator for at least 1 hour.

Once chilled, spoon or pipe the custard into each tart shell.

Before serving, drizzle a generous amount of maple syrup over each tartlet.