Steep 1 black tea bag (such as chai or Earl Grey) in 1/2 cup hot milk, about 4 minutes. Remove the tea bag and whisk the milk with 1/2 cup sugar, 1/4 cup vegetable oil, 1 egg, 1 teaspoon lemon juice and 1/2 teaspoon vanilla in a bowl until smooth, about 2 minutes. Whisk in 1/2 cup flour, 1/8 teaspoon baking soda and a pinch of salt. Pour into 4 buttered microwave-safe teacups until the cups are about two-thirds full. Microwave, one at a time, until puffed and a toothpick comes out clean, about 2 minutes; let cool slightly. Top with whipped cream and cinnamon.