1. Lightly spray the inside of your slow cooker with non-stick cooking spray.
2. In a medium bowl, whisk together the fresh orange juice, orange zest, and granulated sugar until the sugar is mostly dissolved.
3. Add the melted unsalted butter and whisk until well combined.
4. Add the lightly beaten eggs and lemon juice, and whisk until the mixture is smooth.
5. Pour the mixture into your slow cooker. Cover and cook on low heat for 2 to 2.5 hours, stirring every 30 minutes, until the mixture has thickened and coats the back of a spoon.
6. Once the curd has reached the desired consistency, transfer it to a heat-proof bowl and let it cool to room temperature.
7. Once cooled, the curd can be transferred to jars and stored in the refrigerator for up to two weeks
