Toss diced peaches with sugar and lemon juice in a bowl. Allow to stand at room temperature for 30 minutes until a syrup forms. Pour the peach mixture into a fine mesh strainer and allow juices to drain into a bowl. Allow to drain for 30 minutes. Pour the drained peaches in a bowl, press cling wrap tightly onto the top and refrigerate. Save the liquid.

Whisk together the egg yolks and ¼ cup sugar until light in color. In a saucepan whisk together the cream, milk, remaining ½ cup of the sugar, and the salt. Heat over medium-low heat until bubbles appear around the edges of the pan. Whisking constantly, slowly pour in ½ cup of the hot custard base into the egg yolks to temper the eggs. Add an additional ½ cup of hot custard base, continuing to whisk the entire time.

Pour the tempered egg yolks into the saucepan with the rest of the custard base and whisk for 3-4 minutes, or until the temperature is between 170-175. Remove from heat and stir in the vanilla. Strain the custard base through a fine mesh strainer into a clean bowl. Stir in liquid from the fresh peaches and refrigerate for at least 4 hours.

Pour the custard into ice cream maker and churn according to manufacturer's instructions, until it looks like soft-serve ice cream. Add the reserved fresh peaches during the last minute. Move ½ of the custard to an airtight container. Spoon ½ of the peach puree evenly over the custard. Layer the other ½ of the custard on top and spread the remaining puree on top. Using a knife, gently swirl the puree into the custard. Do not over mix. Cover and freeze at least 6 hours until ready to eat.