Begin by heating 1 cup of whole milk in a saucepan over medium heat until it simmers, stirring occasionally. Once simmering, remove from heat and whisk in 2 tablespoons of instant coffee or espresso powder until fully dissolved. Allow this mixture to cool slightly.

In a small saucepan, combine 1/4 cup of water and 3/4 cup of sugar. Bring the mixture to a boil over medium-high heat, stirring constantly for about 1 minute until the sugar completely dissolves.

In a clean mixing bowl, using an electric mixer, beat 3 large egg whites at medium speed until soft peaks form. Gradually pour in the warm sugar syrup while continuously whipping the mixture. Continue beating until the egg whites become glossy and hold stiff peaks.

In a separate bowl, mix 2 cups of plain Greek yogurt and 1 teaspoon of vanilla extract. Gradually pour in the cooled milk mixture while stirring gently to ensure everything is well combined. Carefully fold in one-third of the meringue, followed by the remaining meringue until no streaks remain.

Pour the combined mixture into your ice cream maker and churn according to the manufacturer’s instructions, typically about 20-25 minutes until it thickens and forms a soft-serve consistency.

Transfer your Coffee Frozen Yogurt to a freezer-safe container, smooth the top, seal tightly, and place in the freezer for at least 2-3 hours or until it's firm.