How to Make It
Combine strawberries, blueberries, salt, and 2 tablespoons of the maple syrup in a medium bowl. Let stand, stirring occasionally, until juices run, about 10 minutes.
Meanwhile, beat heavy cream with an electric mixer on medium-high until stiff peaks form, about 2 minutes. Fold in yogurt, vanilla extract, and remaining 3 tablespoons maple syrup; beat until combined, about 1 minute. Cover and chill until ready to use. (Can be made 1 day ahead.)
To assemble trifle, place half of the muffin pieces in an even layer on the bottom of a 3-quart trifle dish. Top evenly with 1 cup of the whipped yogurt mixture, 2 cups of the berry mixture, 1 cup of the granola, another 1 cup whipped yogurt mixture, and 1 1/2 cups sliced bananas. Repeat layers once, ending with whipped yogurt mixture. Garnish with remaining 1/2 cup berry mixture and bananas.4. Serve immediately, or can be made up to 2 hours ahead.