Whisk the milk, coffee, pumpkin, maple syrup, vanilla, cinnamon, ginger, nutmeg, cloves and salt in a 5-quart slow cooker until smooth.
Cover and cook on low for 1 1/2 to 2 hours, whisking after 45 minutes and again before serving.
Check the temperature after 90 minutes and switch to warm once the latte reaches 150°F to 160°F.
Do not let the mixture simmer, because boiled milk develops a skin and a cooked flavor.
Whisk vigorously just before ladling to redistribute the pumpkin and spices.
Hold on warm for no more than 2 hours, stirring every 30 minutes.