Preheat your oven to 350°F (175°C). Prepare a 9-inch round cake pan by greasing it or lining it with parchment paper.

In a mixing bowl, whisk together the flour, baking powder, baking soda, salt, and ground cinnamon. Set aside.

In another bowl, using a hand mixer or stand mixer, cream the softened butter and granulated sugar until the mixture is light and fluffy — this usually takes about 2-3 minutes.

Add the eggs one at a time, mixing well after each addition. Pour in the vanilla extract and mix until combined.

Gradually add the cooled Earl Grey tea to the butter and sugar mixture, mixing on low speed.

Slowly add the dry ingredients to the wet mixture, mixing just until combined. Be careful not to overmix.

Gently fold in the diced fresh peaches until they are evenly distributed throughout the batter.

Transfer the batter to your prepared cake pan and smooth the top with a spatula.

Place in the preheated oven and bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.

Allow the cake to cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely. Dust with powdered sugar or serve with whipped cream if desired.