Step 1

In a medium saucepan, combine the heavy cream, milk, 1/2 cup sugar, and a pinch of salt. Warm over medium heat, stirring occasionally, until the sugar dissolves and the mixture is hot but not boiling.

Step 2

In a separate bowl, whisk together the egg yolks and the remaining 1/4 cup sugar until well blended.

Step 3

Gradually temper the egg yolks by adding a small amount of the hot cream mixture, whisking constantly. Repeat until about half of the cream mixture has been added.

Step 4

Pour the egg yolk mixture back into the saucepan with the remaining cream mixture. Cook over low heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon (about 170-175°F).

Step 5

Remove from heat and strain through a fine-mesh sieve into a clean bowl. Stir in the vanilla extract, mashed bananas, and lemon juice. Cover and chill in the refrigerator for at least 4 hours, or overnight.

Step 6

Once chilled, churn the mixture in an ice cream maker according to the manufacturer's instructions.

Step 7

During the last few minutes of churning, add the crushed Nilla Wafers to the ice cream.

Step 8

Transfer the ice cream to a freezer-safe container, layering it with additional crushed Nilla Wafers. Freeze until firm, at least 4 hours or overnight.

Step 9

Serve garnished with more Nilla Wafers and optional whipped cream.