Pour 1 cup almond milk into a small saucepan. Add cornstarch and heat over medium heat. Cook, stirring constantly, until bubbly, 3 to 5 minutes. Remove from heat; keep stirring for 30 seconds.
Pour remaining almond milk into a bowl; add pudding mix. Mix with an electric mixer on low speed until very thick, about 1 minute. Add cornstarch mixture to the pudding mixture. Mix at low speed for 1 minute more.
Transfer pudding to 4 individual serving bowls. Cover and refrigerate if desired.
