Preheat the oven to 350°F. Coat a 9-by-5-inch loaf pan with nonstick cooking spray. Line the pan with parchment paper along the long sides, leaving approximately 1 inch of overhang on each side to make removing the cake easier. Set aside.

In a large mixing bowl, whisk together the warm melted butter, Earl Grey tea leaves, and ground cardamom until combined. Let steep for 10 minutes to infuse the butter with the flavors of the tea and spice.

Add the sugar, milk, eggs, orange zest and vanilla extract to the butter mixture. Whisk until smooth and well combined.

In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

Add the dry ingredients to the wet ingredients and gently fold until just combined. Do not overmix.

Transfer the batter to the prepared loaf pan, spreading it evenly. Bake for 40 to 50 minutes, or until a cake tester inserted into the center comes out clean.

Let the cake cool in the pan for approximately 10 minutes. Using the parchment paper overhang, carefully lift the cake from the pan and transfer it to a wire rack.

Once you’ve removed the cake from the oven, prepare the orange and Grand Marnier syrup. In a small saucepan, combine the orange juice and sugar. Heat gently over low heat, stirring until the sugar has completely dissolved. Remove from the heat and stir in the Grand Marnier.

Once you’ve removed the cake from the pan, use a pastry brush to lightly brush the syrup over the top and, if desired, the sides of the loaf. Apply it gradually, allowing the syrup to absorb into the cake.

Allow the cake to cool completely before slicing and serving.