067 / 75 · Sweet finishes and small bakes
Banana and Peanut Butter Steamed Squares
4 soft cake squares, one square per small dessert portion · Active 16 min · Cook 5 min · Total 25 min (warm service)
Print recipe · PDFRipe banana and smooth peanut butter make a small, soft cake with enough flavor to serve plain. Mash the banana well so it becomes part of the batter rather than leaving a cold lump. A shallow square dish gives the center a fair chance to set before the edges dry. The four pieces are tender steamed squares, not browned brownies.
Mash away the large lumps
Small banana flecks are fine, but a large piece can make a center check misleading. Mix the mashed fruit with the egg and milk before folding in flour. Smooth peanut butter should be stirred in its jar first so its oil is evenly distributed. The formula has no separate peanut drizzle or nut garnish.
Let the shape settle before cutting
The mandatory covered stand follows the full thermal endpoint. A further short uncovered rest then makes the cake easier to divide. Cut across the cooked center to check for a set crumb without a wet floury seam; do not taste raw batter. The surface stays pale because there is no oven or grill stage.
Ingredients
- 100 g ripe banana flesh (3½ oz), peel excluded, thoroughly mashed
- 70 g all-purpose flour (2½ oz), for complete cooking under its label guidance
- 1 large egg, 50 g/1¾ oz without shell, fully beaten
- 30 ml pasteurized milk (2 tbsp)
- 20 g smooth peanut butter (about 1 tbsp plus 1 tsp), stirred before measuring
- 10 g granulated sugar (about 2½ tsp)
- 5 ml neutral oil (1 tsp), all for greasing the dish
- 2 g baking powder (about ½ tsp)
- 0.5 g ground cinnamon (about ¼ tsp)
- 0.3 g fine salt, a small pinch
Set out
1000 W microwave with turntable, Kitchen scale and measuring jug, Spoon, Fork or small whisk, Oven mitts, Food thermometer used outside the microwave, Microwave-safe square dish, at least 1 L/about 1 US qt measured usable capacity, with 14 ×14 cm/about 5½ ×5½ in usable inside base and about 5–6 cm/2–2⅓ in depth, Microwave-safe vented cover, Mixing bowl, Knife and board, Spreading utensil, Four small plates
Allergens
Wheat, Egg, Milk, Peanuts. Check labels and substitutions.
Make it
- Spread all 5 ml oil over the bottom and sides of the 1 L square dish. In the mixing bowl, mash the banana thoroughly with the fork, then whisk in the beaten egg, milk, peanut butter and sugar until even.
- Add the flour, baking powder, cinnamon and salt. Stir until no dry pockets remain. Scrape all the batter into the prepared dish and level it. The raw batter should make a shallow layer, about 2 cm/¾ in or less, and stay below half the dish’s usable capacity.
- Cover with a vent and microwave at 1000 W baseline on 70% power for 3 minutes. Rotate the dish half a turn and continue for 1–2 minutes. Check several points, including the deepest center, for at least 165°F/74°C and a fully set crumb without a wet floury seam when cut. Use further 20-second bursts if needed; do not taste raw batter, and follow any longer minimum flour-label process.
- Stand covered with the vent open for 2 minutes. Uncover carefully and rest for 5 minutes to settle the shape. Cut the whole cake into four equal squares and serve one per small dessert portion. There is no extra sauce or topping.
Four is the complete cut
Divide the whole measured cake into four equal pieces. A larger decorative extra square would not be another portion from this batch.
A soft finish
The crumb is cooked but tender. It is not intended to become a crisp-edged oven cake in the microwave.
Ingredient labels
Flour contains wheat/gluten. Peanut butter may have additional ingredients. The almond-butter version changes the nut ingredient rather than making the cake generally nut-free.
A useful detail
The 25-minute warm-service plan allows 10 minutes of preparation, up to 5 minutes of heating, the 2-minute covered stand, a 5-minute shape-setting rest and 3 minutes to check and cut. Baseline oven power is 1000 W. Extra center-check bursts can extend the total; the banana does not justify a raw or molten center.
Another way
- Replace 20 g/about 1 tbsp plus 1 tsp peanut butter with 20 g/0.7 oz smooth almond butter. Almond becomes the nut ingredient; check labels and cross-contact suitability.
- Replace 0.5 g/about ¼ tsp cinnamon with 0.5 g/about ¼ tsp ground ginger for a different warm spice. Keep the full banana and liquid amounts unchanged.
Keep it well
Refrigerate fully cooked squares in shallow covered storage within 2 hours, or 1 hour above 90°F/32°C, at 40°F/4°C or below. Use within 2 days. Reheat only the needed square with 5 ml/1 tsp water under a vented cover in short low-power bursts; stand 2 minutes and verify 165°F/74°C throughout. Never chill a partly cooked square to finish later.